Add standalone Go build alongside VSCode extension

Ports all five tools to a single 7.5 MB Windows exe with an embedded WebView2 window, file-based config, single-instance focus, and clean shutdown. Adds build.ps1 to build both targets from one command. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-12 01:15:39 +08:00
parent 859c7d9e7c
commit f123cbfc4a
17 changed files with 2156 additions and 0 deletions
--- a/standalone/.gitignore
+++ b/standalone/.gitignore
@@ -0,0 +1,4 @@
+hpl-toolbox.exe
+config.json
+.hpltoolbox.lock
+debug.log
--- a/standalone/applovin.go
+++ b/standalone/applovin.go
@@ -0,0 +1,302 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	urlpkg "net/url"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+func ApplovinPage(w http.ResponseWriter, r *http.Request) {
+	body := `
+<h2>AppLovin Playable Preview (QR)</h2>
+<p class="hint" style="margin-top:0;">Upload HTML files to p.applov.in and get QR codes to scan with the AppLovin Playable Preview app.</p>
+
+<div style="display:flex;align-items:center;gap:8px;margin-bottom:8px;">
+  <button id="pick" class="secondary">Choose files...</button>
+  <span id="fileName" class="hint">(no files)</span>
+</div>
+<div style="display:flex;gap:8px;">
+  <button id="upload">Upload to AppLovin</button>
+</div>
+
+<div id="status" style="margin-top:12px;min-height:20px;"></div>
+<div id="results" style="margin-top:12px;display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:12px;"></div>
+
+<style>
+  .result { padding:10px; background:#252526; border-left:3px solid #007fd4; word-break:break-all; }
+  .result-actions { margin-top:8px; display:flex; gap:8px; flex-wrap:wrap; }
+</style>
+
+<script>
+const pickBtn = document.getElementById('pick');
+const uploadBtn = document.getElementById('upload');
+const fileNameEl = document.getElementById('fileName');
+const statusEl = document.getElementById('status');
+const resultsEl = document.getElementById('results');
+let selectedPaths = [];
+
+pickBtn.addEventListener('click', async () => {
+  const r = await fetch('/api/applovin/pick', { method: 'POST' });
+  const j = await r.json();
+  if (j.files && j.files.length) {
+    selectedPaths = j.files.map(f => f.path);
+    const names = j.files.map(f => f.name);
+    fileNameEl.textContent = names.length === 1
+      ? names[0]
+      : names.length + ' files: ' + names.slice(0,3).join(', ') + (names.length > 3 ? '...' : '');
+  }
+});
+
+uploadBtn.addEventListener('click', async () => {
+  statusEl.textContent = '';
+  resultsEl.innerHTML = '';
+  if (!selectedPaths.length) {
+    statusEl.innerHTML = '<span class="err">Pick at least one HTML file first.</span>';
+    return;
+  }
+  uploadBtn.disabled = true;
+  try {
+    const res = await fetch('/api/applovin/upload', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ paths: selectedPaths }),
+    });
+    if (!res.ok || !res.body) {
+      statusEl.innerHTML = '<span class="err">Upload failed.</span>';
+      uploadBtn.disabled = false;
+      return;
+    }
+    const reader = res.body.getReader();
+    const dec = new TextDecoder();
+    let buf = '';
+    while (true) {
+      const { value, done } = await reader.read();
+      if (done) break;
+      buf += dec.decode(value, { stream: true });
+      let nl;
+      while ((nl = buf.indexOf('\n')) >= 0) {
+        const line = buf.slice(0, nl); buf = buf.slice(nl + 1);
+        if (!line.trim()) continue;
+        handle(JSON.parse(line));
+      }
+    }
+  } catch (e) {
+    statusEl.innerHTML = '<span class="err">' + (e.message || e) + '</span>';
+  } finally {
+    uploadBtn.disabled = false;
+  }
+});
+
+function escapeHtml(s){
+  return String(s).replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c]));
+}
+
+function handle(m) {
+  if (m.type === 'status') {
+    statusEl.textContent = m.message;
+  } else if (m.type === 'fileError') {
+    const wrap = document.createElement('div');
+    wrap.className = 'result';
+    wrap.innerHTML = '<div><strong>' + escapeHtml(m.name) + '</strong></div>' +
+      '<div class="err" style="margin-top:6px;">' + escapeHtml(m.message) + '</div>';
+    resultsEl.appendChild(wrap);
+  } else if (m.type === 'fileResult') {
+    const wrap = document.createElement('div');
+    wrap.className = 'result';
+    wrap.innerHTML =
+      '<div style="font-weight:600;margin-bottom:8px;">' + escapeHtml(m.name) + '</div>' +
+      '<div style="text-align:center;margin-bottom:8px;">' +
+        '<img src="' + m.qrImg + '" style="background:#fff;padding:8px;border-radius:4px;max-width:100%;" />' +
+      '</div>' +
+      '<div style="font-size:11px;opacity:0.8;">Hash: ' + escapeHtml(m.hash) + '</div>';
+    const actions = document.createElement('div');
+    actions.className = 'result-actions';
+    const copyHash = document.createElement('button');
+    copyHash.textContent = 'Copy Hash';
+    copyHash.onclick = () => fetch('/api/clipboard', {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({text:m.hash})});
+    const copyUrl = document.createElement('button');
+    copyUrl.textContent = 'Copy URL';
+    copyUrl.className = 'secondary';
+    copyUrl.onclick = () => fetch('/api/clipboard', {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({text:m.previewUrl})});
+    const openBtn = document.createElement('button');
+    openBtn.textContent = 'Open';
+    openBtn.className = 'secondary';
+    openBtn.onclick = () => fetch('/api/open', {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({url:m.previewUrl})});
+    actions.appendChild(copyHash); actions.appendChild(copyUrl); actions.appendChild(openBtn);
+    wrap.appendChild(actions);
+    resultsEl.appendChild(wrap);
+  } else if (m.type === 'done') {
+    statusEl.innerHTML = '<span class="ok">Done.</span>';
+  }
+}
+</script>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/applovin", "AppLovin Upload", body)))
+}
+
+func ApplovinPick(w http.ResponseWriter, r *http.Request) {
+	picked := PickFiles(
+		"Select HTML files",
+		[]FileFilter{{Name: "HTML", Extensions: []string{"html", "htm"}}},
+		true, "",
+	)
+	files := make([]map[string]string, 0, len(picked))
+	for _, p := range picked {
+		files = append(files, map[string]string{"path": p, "name": filepath.Base(p)})
+	}
+	writeJSON(w, map[string]any{"files": files})
+}
+
+func ApplovinUpload(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Paths []string `json:"paths"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	cookie := LoadConfig().Applovin.Cookie
+
+	w.Header().Set("Content-Type", "application/x-ndjson")
+	flusher, _ := w.(http.Flusher)
+
+	send := func(obj any) {
+		data, _ := json.Marshal(obj)
+		_, _ = w.Write(append(data, '\n'))
+		if flusher != nil {
+			flusher.Flush()
+		}
+	}
+
+	htmlRx := regexp.MustCompile(`(?i)\.html?$`)
+
+	buildForm := func(filePath string) (*bytes.Buffer, string, error) {
+		data, err := os.ReadFile(filePath)
+		if err != nil {
+			return nil, "", err
+		}
+		var buf bytes.Buffer
+		mw := multipart.NewWriter(&buf)
+		fw, err := createFormFileWithType(mw, "file", filepath.Base(filePath), "text/html")
+		if err != nil {
+			return nil, "", err
+		}
+		if _, err := fw.Write(data); err != nil {
+			return nil, "", err
+		}
+		if err := mw.Close(); err != nil {
+			return nil, "", err
+		}
+		return &buf, mw.FormDataContentType(), nil
+	}
+
+	doPost := func(url string, body *bytes.Buffer, contentType string) (int, string, error) {
+		req, err := http.NewRequest("POST", url, body)
+		if err != nil {
+			return 0, "", err
+		}
+		req.Header.Set("Content-Type", contentType)
+		req.Header.Set("Accept", "application/json, text/javascript, */*; q=0.01")
+		req.Header.Set("Origin", "https://p.applov.in")
+		req.Header.Set("Referer", "https://p.applov.in/playablePreview?create=1&qr=1")
+		req.Header.Set("X-Requested-With", "XMLHttpRequest")
+		req.Header.Set("User-Agent", "Mozilla/5.0 (HPL-Toolbox-Standalone)")
+		if cookie != "" {
+			req.Header.Set("Cookie", "__Host-APPLOVINID="+cookie)
+		}
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			return 0, "", err
+		}
+		defer resp.Body.Close()
+		out, _ := io.ReadAll(resp.Body)
+		return resp.StatusCode, string(out), nil
+	}
+
+	for i, filePath := range req.Paths {
+		fileName := filepath.Base(filePath)
+		idx := i + 1
+		fileErr := func(msg string) {
+			send(map[string]any{"type": "fileError", "name": fileName, "message": msg})
+		}
+
+		if filePath == "" || !fileExists(filePath) {
+			fileErr("File missing")
+			continue
+		}
+		if !htmlRx.MatchString(filePath) {
+			fileErr("Must be .html")
+			continue
+		}
+
+		send(map[string]any{"type": "status", "message": fmt.Sprintf("[%d/%d] Validating %s...", idx, len(req.Paths), fileName)})
+
+		body, ct, err := buildForm(filePath)
+		if err != nil {
+			fileErr("Read failed: " + err.Error())
+			continue
+		}
+		status, respText, err := doPost("https://p.applov.in/validateHTMLContent", body, ct)
+		if err != nil {
+			fileErr("Network (validate): " + err.Error())
+			continue
+		}
+		if status < 200 || status >= 300 {
+			fileErr(fmt.Sprintf("Validate HTTP %d: %s", status, truncate(respText, 300)))
+			continue
+		}
+		var vJSON map[string]any
+		_ = json.Unmarshal([]byte(respText), &vJSON)
+		if code, ok := vJSON["code"]; ok {
+			if codeNum, isNum := code.(float64); isNum && codeNum != 200 {
+				fileErr("Validation failed: " + truncate(respText, 300))
+				continue
+			}
+		}
+
+		send(map[string]any{"type": "status", "message": fmt.Sprintf("[%d/%d] Uploading %s...", idx, len(req.Paths), fileName)})
+
+		body, ct, err = buildForm(filePath)
+		if err != nil {
+			fileErr("Read failed: " + err.Error())
+			continue
+		}
+		status, respText, err = doPost("https://p.applov.in/getCachedAdURL", body, ct)
+		if err != nil {
+			fileErr("Network (cache): " + err.Error())
+			continue
+		}
+		if status < 200 || status >= 300 {
+			fileErr(fmt.Sprintf("Cache HTTP %d: %s", status, truncate(respText, 300)))
+			continue
+		}
+		var cJSON map[string]any
+		if err := json.Unmarshal([]byte(respText), &cJSON); err != nil {
+			fileErr("Non-JSON: " + truncate(respText, 300))
+			continue
+		}
+		hash, _ := cJSON["results"].(string)
+		if hash == "" {
+			fileErr("No hash in response: " + truncate(respText, 300))
+			continue
+		}
+
+		send(map[string]any{
+			"type":       "fileResult",
+			"name":       fileName,
+			"hash":       hash,
+			"previewUrl": "https://p.applov.in/getPreviewHTML?preview=" + hash,
+			"pageUrl":    "https://p.applov.in/playablePreview?preview=" + hash + "&qr=1",
+			"qrImg":      "https://api.qrserver.com/v1/create-qr-code/?size=250x250&data=" + urlpkg.QueryEscape(hash),
+		})
+	}
+	send(map[string]any{"type": "done"})
+}
--- a/standalone/assets/qrcode.min.js
+++ b/standalone/assets/qrcode.min.js
--- a/standalone/base64.go
+++ b/standalone/base64.go
@@ -0,0 +1,289 @@
+package main
+
+import (
+	"encoding/json"
+	"io/fs"
+	"net/http"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+func Base64Page(w http.ResponseWriter, r *http.Request) {
+	body := `
+<h2>Base64 Asset Scanner</h2>
+<div style="display:flex;gap:8px;align-items:center;margin-bottom:8px;">
+  <input id="folder" type="text" placeholder="Folder to scan recursively..." style="flex:1;" />
+  <button id="pickFolder">Browse Folder...</button>
+  <button id="pickFiles">Pick Files...</button>
+  <button id="scan">Scan</button>
+</div>
+<div id="selection" class="hint"></div>
+<div id="status" style="margin-top:8px;"></div>
+<div id="results" style="margin-top:8px;"></div>
+
+<style>
+  .row-result { display:flex; gap:8px; padding:2px 0; font-family:Consolas, monospace; font-size:12px; }
+  .mark { width:14px; flex-shrink:0; font-weight:bold; }
+  .mark.ok { color:#3fb950; } .mark.bad { color:#f85149; }
+  .file-name { word-break:break-all; }
+  .assets { opacity:0.7; margin-left:6px; word-break:break-all; }
+  .summary { opacity:0.8; margin-bottom:6px; }
+</style>
+
+<script>
+const folderEl = document.getElementById('folder');
+const statusEl = document.getElementById('status');
+const resultsEl = document.getElementById('results');
+const selectionEl = document.getElementById('selection');
+let pickedFiles = [];
+function clearFiles(){ pickedFiles = []; selectionEl.textContent = ''; }
+folderEl.addEventListener('input', clearFiles);
+
+document.getElementById('pickFolder').addEventListener('click', async () => {
+  const r = await fetch('/api/base64/pickFolder', { method: 'POST' });
+  const j = await r.json();
+  if (j.path) { folderEl.value = j.path; clearFiles(); }
+});
+document.getElementById('pickFiles').addEventListener('click', async () => {
+  const r = await fetch('/api/base64/pickFiles', { method: 'POST' });
+  const j = await r.json();
+  if (j.paths && j.paths.length) {
+    pickedFiles = j.paths;
+    folderEl.value = '';
+    selectionEl.textContent = pickedFiles.length + ' file(s) selected';
+  }
+});
+document.getElementById('scan').addEventListener('click', async () => {
+  statusEl.textContent = 'Scanning...';
+  resultsEl.innerHTML = '';
+  let payload;
+  if (pickedFiles.length) payload = { files: pickedFiles };
+  else {
+    const folder = folderEl.value.trim();
+    if (!folder) { statusEl.textContent = 'Pick a folder or files first.'; return; }
+    payload = { folder };
+  }
+  const r = await fetch('/api/base64/scan', { method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify(payload) });
+  const j = await r.json();
+  if (j.error) { statusEl.textContent = 'Error: ' + j.error; return; }
+  const total = j.results.length;
+  const flagged = j.results.filter(r => !r.ok).length;
+  statusEl.innerHTML = '<div class="summary">Scanned ' + total + ' HTML file(s). ' + flagged + ' contain non-base64 assets.</div>';
+  resultsEl.innerHTML = '';
+  for (const rr of j.results) {
+    const row = document.createElement('div');
+    row.className = 'row-result';
+    const mark = document.createElement('span');
+    mark.className = 'mark ' + (rr.ok ? 'ok' : 'bad');
+    mark.textContent = rr.ok ? '✓' : '✗';
+    const name = document.createElement('span');
+    name.className = 'file-name';
+    name.textContent = rr.file;
+    row.appendChild(mark); row.appendChild(name);
+    if (!rr.ok) {
+      const a = document.createElement('span');
+      a.className = 'assets';
+      a.textContent = '— ' + rr.assets.join(', ');
+      row.appendChild(a);
+    }
+    resultsEl.appendChild(row);
+  }
+});
+</script>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/base64", "Base64 Scanner", body)))
+}
+
+func Base64PickFolder(w http.ResponseWriter, r *http.Request) {
+	p := PickFolder("Select folder to scan", "")
+	writeJSON(w, map[string]any{"path": p})
+}
+
+func Base64PickFiles(w http.ResponseWriter, r *http.Request) {
+	paths := PickFiles(
+		"Select HTML files",
+		[]FileFilter{{Name: "HTML", Extensions: []string{"html", "htm"}}},
+		true, "",
+	)
+	writeJSON(w, map[string]any{"paths": paths})
+}
+
+type scanResult struct {
+	File   string   `json:"file"`
+	OK     bool     `json:"ok"`
+	Assets []string `json:"assets"`
+}
+
+func Base64Scan(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Folder string   `json:"folder"`
+		Files  []string `json:"files"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"results": []scanResult{}, "error": err.Error()})
+		return
+	}
+
+	var targets []string
+	var baseDir string
+
+	if len(req.Files) > 0 {
+		for _, f := range req.Files {
+			if fileExists(f) {
+				targets = append(targets, f)
+			}
+		}
+		if len(targets) > 0 {
+			baseDir = commonBaseDir(targets)
+		}
+	} else if req.Folder != "" && fileExists(req.Folder) {
+		targets = collectHTMLFiles(req.Folder)
+		baseDir = req.Folder
+	} else {
+		writeJSON(w, map[string]any{"results": []scanResult{}, "error": "Pick a folder or files first"})
+		return
+	}
+
+	results := []scanResult{}
+	for _, file := range targets {
+		data, err := os.ReadFile(file)
+		if err != nil {
+			continue
+		}
+		offenders := findNonBase64Assets(string(data))
+		display := file
+		if baseDir != "" {
+			rel, err := filepath.Rel(baseDir, file)
+			if err == nil && rel != "" {
+				display = rel
+			} else {
+				display = filepath.Base(file)
+			}
+		}
+		results = append(results, scanResult{
+			File:   display,
+			OK:     len(offenders) == 0,
+			Assets: offenders,
+		})
+	}
+	writeJSON(w, map[string]any{"results": results})
+}
+
+func commonBaseDir(files []string) string {
+	if len(files) == 0 {
+		return ""
+	}
+	if len(files) == 1 {
+		return filepath.Dir(files[0])
+	}
+	split := make([][]string, len(files))
+	for i, f := range files {
+		split[i] = strings.Split(filepath.Dir(f), string(filepath.Separator))
+	}
+	first := split[0]
+	i := 0
+	for i < len(first) {
+		match := true
+		for _, parts := range split {
+			if i >= len(parts) || parts[i] != first[i] {
+				match = false
+				break
+			}
+		}
+		if !match {
+			break
+		}
+		i++
+	}
+	return strings.Join(first[:i], string(filepath.Separator))
+}
+
+func collectHTMLFiles(root string) []string {
+	var out []string
+	htmlRx := regexp.MustCompile(`(?i)\.html?$`)
+	_ = filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return nil
+		}
+		if d.IsDir() {
+			name := d.Name()
+			if name == "node_modules" || name == ".git" {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+		if htmlRx.MatchString(d.Name()) {
+			out = append(out, path)
+		}
+		return nil
+	})
+	return out
+}
+
+var (
+	scriptBlockRx = regexp.MustCompile(`(?is)<script\b[^>]*>.*?</script>`)
+	attrRx        = regexp.MustCompile(`(?i)\b(?:src|href|poster|data-src)\s*=\s*("([^"]*)"|'([^']*)')`)
+	cssUrlRx      = regexp.MustCompile(`(?i)url\(\s*(?:"([^"]*)"|'([^']*)'|([^)]*))\s*\)`)
+	base64DataRx  = regexp.MustCompile(`(?i)^data:[^;,]*;base64,`)
+	mailTelRx     = regexp.MustCompile(`(?i)^(mailto:|tel:)`)
+)
+
+func findNonBase64Assets(htmlSrc string) []string {
+	markup := scriptBlockRx.ReplaceAllString(htmlSrc, "")
+	seen := map[string]bool{}
+	var out []string
+	add := func(u string) {
+		if u == "" || seen[u] {
+			return
+		}
+		seen[u] = true
+		out = append(out, u)
+	}
+
+	for _, m := range attrRx.FindAllStringSubmatch(markup, -1) {
+		url := m[2]
+		if url == "" {
+			url = m[3]
+		}
+		url = strings.TrimSpace(url)
+		if url == "" {
+			continue
+		}
+		if isAssetReference(url) && !base64DataRx.MatchString(url) {
+			add(url)
+		}
+	}
+	for _, m := range cssUrlRx.FindAllStringSubmatch(markup, -1) {
+		url := m[1]
+		if url == "" {
+			url = m[2]
+		}
+		if url == "" {
+			url = m[3]
+		}
+		url = strings.TrimSpace(url)
+		if url == "" {
+			continue
+		}
+		if !base64DataRx.MatchString(url) {
+			add(url)
+		}
+	}
+	if out == nil {
+		out = []string{}
+	}
+	return out
+}
+
+func isAssetReference(url string) bool {
+	if strings.HasPrefix(url, "#") || strings.HasPrefix(strings.ToLower(url), "javascript:") {
+		return false
+	}
+	if mailTelRx.MatchString(url) {
+		return false
+	}
+	return true
+}
--- a/standalone/daily.go
+++ b/standalone/daily.go
@@ -0,0 +1,131 @@
+package main
+
+import (
+	"encoding/json"
+	"html"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+)
+
+func DailyPage(w http.ResponseWriter, r *http.Request) {
+	cfg := LoadConfig()
+	today := time.Now().Format("2006-01-02")
+	lastProject := html.EscapeString(cfg.DailyUpdate.LastProject)
+
+	body := `
+<h2>Daily Update</h2>
+<div class="hint" style="margin-bottom:12px;">Submit copies the formatted text to your clipboard.</div>
+
+<div style="max-width:520px;">
+  <label style="display:block;margin-top:8px;font-size:12px;opacity:0.85;">Date</label>
+  <input type="date" id="date" value="` + today + `" style="width:100%;" />
+
+  <label style="display:block;margin-top:12px;font-size:12px;opacity:0.85;">Status</label>
+  <select id="status" style="width:100%;">
+    <option>Started</option><option>Progress</option><option>Finished</option>
+    <option>Client Feedback</option><option>For OT</option>
+  </select>
+
+  <label style="display:block;margin-top:12px;font-size:12px;opacity:0.85;">Project</label>
+  <input type="text" id="project" placeholder="Project name" value="` + lastProject + `" style="width:100%;" />
+
+  <label style="display:block;margin-top:12px;font-size:12px;opacity:0.85;">Remarks</label>
+  <textarea id="remarks" placeholder="What did you do?" style="width:100%;min-height:96px;"></textarea>
+
+  <button id="submit" style="margin-top:16px;">Submit</button>
+  <div id="status-msg" style="margin-top:12px;min-height:18px;"></div>
+</div>
+
+<script>
+document.getElementById('submit').addEventListener('click', async () => {
+  const payload = {
+    date: document.getElementById('date').value,
+    status: document.getElementById('status').value,
+    project: document.getElementById('project').value.trim(),
+    remarks: document.getElementById('remarks').value.trim(),
+  };
+  const statusEl = document.getElementById('status-msg');
+  statusEl.textContent = 'Copying...';
+  try {
+    const res = await fetch('/api/daily/submit', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(payload),
+    });
+    const j = await res.json();
+    if (j.ok) {
+      statusEl.innerHTML = '<span class="ok">Copied to clipboard.</span>';
+    } else {
+      statusEl.innerHTML = '<span class="err">' + (j.error || 'Failed') + '</span>';
+    }
+  } catch (e) {
+    statusEl.innerHTML = '<span class="err">' + (e.message || e) + '</span>';
+  }
+});
+</script>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/daily", "Daily Update", body)))
+}
+
+type dailySubmitReq struct {
+	Date    string `json:"date"`
+	Status  string `json:"status"`
+	Project string `json:"project"`
+	Remarks string `json:"remarks"`
+}
+
+func DailySubmit(w http.ResponseWriter, r *http.Request) {
+	var req dailySubmitReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	text := formatDailyMessage(req)
+	if err := CopyToClipboard(text); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	cfg := LoadConfig()
+	cfg.DailyUpdate.LastProject = req.Project
+	_ = SaveConfig(cfg)
+	writeJSON(w, map[string]any{"ok": true, "text": text})
+}
+
+func formatDailyMessage(p dailySubmitReq) string {
+	bullets := []string{}
+	for _, line := range strings.Split(p.Remarks, "\n") {
+		t := strings.TrimRight(line, "\r")
+		t = regexp.MustCompile(`^\s*[-*]\s*`).ReplaceAllString(t, "")
+		t = strings.TrimSpace(t)
+		if t != "" {
+			bullets = append(bullets, "- "+t)
+		}
+	}
+	lines := []string{
+		"Date: " + formatDailyDate(p.Date),
+		"Status: " + p.Status,
+		"Project: " + p.Project,
+		"Remarks:",
+		strings.Join(bullets, "\n"),
+	}
+	if p.Status == "For OT" {
+		lines = append(lines, "@Joyce Lanot , @Reland Pigte, @Anthony Castor, @Angela Grace")
+	}
+	return strings.Join(lines, "\n")
+}
+
+func formatDailyDate(iso string) string {
+	t, err := time.Parse("2006-01-02", iso)
+	if err != nil {
+		return iso
+	}
+	return t.Format("01/02/2006")
+}
+
+func writeJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(v)
+}
--- a/standalone/go.mod
+++ b/standalone/go.mod
@@ -0,0 +1,9 @@
+module hpltoolbox
+
+go 1.22
+
+require (
+	github.com/jchv/go-webview2 v0.0.0-20260205173254-56598839c808 // indirect
+	github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1 // indirect
+	golang.org/x/sys v0.0.0-20210218145245-beda7e5e158e // indirect
+)
--- a/standalone/go.sum
+++ b/standalone/go.sum
@@ -0,0 +1,7 @@
+github.com/jchv/go-webview2 v0.0.0-20260205173254-56598839c808 h1:ftnsTqIUH57XQEF+PnXX9++nlHCzdkuB5zbWyMMruZo=
+github.com/jchv/go-webview2 v0.0.0-20260205173254-56598839c808/go.mod h1:rWifBlzkgrvd7zUqlfq91sWt3473OikgnglnIILx/Jo=
+github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1 h1:njuLRcjAuMKr7kI3D85AXWkw6/+v9PwtV6M6o11sWHQ=
+github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1/go.mod h1:alcuEEnZsY1WQsagKhZDsoPCRoOijYqhZvPwLG0kzVs=
+golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210218145245-beda7e5e158e h1:f5mksnk+hgXHnImpZoWj64ja99j9zV7YUgrVG95uFE4=
+golang.org/x/sys v0.0.0-20210218145245-beda7e5e158e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
--- a/standalone/home.go
+++ b/standalone/home.go
@@ -0,0 +1,19 @@
+package main
+
+import "net/http"
+
+func HomePage(w http.ResponseWriter, r *http.Request) {
+	body := `
+<h2>HPL Toolbox</h2>
+<p class="hint">Standalone build. Pick a tool from the top bar.</p>
+<ul style="line-height:1.9;">
+  <li><a href="/plec" style="color:#9cdcfe;">PLEC Upload</a> — Upload HTML to the internal PLEC server</li>
+  <li><a href="/applovin" style="color:#9cdcfe;">AppLovin Demo Upload</a> — Upload to p.applov.in (QR preview)</li>
+  <li><a href="/base64" style="color:#9cdcfe;">Base64 Scanner</a> — Find non-base64 assets in HTML</li>
+  <li><a href="/daily" style="color:#9cdcfe;">Daily Update</a> — Compose &amp; copy a daily status</li>
+  <li><a href="/mobile" style="color:#9cdcfe;">Send To Mobile</a> — Share HTML to a phone via LAN + QR</li>
+</ul>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/", "Home", body)))
+}
--- a/standalone/hpl.ico
+++ b/standalone/hpl.ico
--- a/standalone/layout.go
+++ b/standalone/layout.go
@@ -0,0 +1,73 @@
+package main
+
+import "strings"
+
+const SharedCSS = `
+  :root { color-scheme: dark; }
+  body {
+    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+    background: #1e1e1e; color: #ddd;
+    margin: 0; padding: 0;
+  }
+  .topbar {
+    display: flex; align-items: center; gap: 8px;
+    padding: 8px 16px; background: #252526; border-bottom: 1px solid #333;
+    font-size: 13px;
+  }
+  .topbar a { color: #9cdcfe; text-decoration: none; padding: 4px 10px; border-radius: 3px; }
+  .topbar a:hover { background: #2a2d2e; }
+  .topbar a.active { background: #094771; color: #fff; }
+  .content { padding: 16px; max-width: 980px; margin: 0 auto; }
+  h2 { margin-top: 0; font-weight: 500; }
+  input[type=text], input[type=date], select, textarea {
+    box-sizing: border-box; padding: 6px 8px;
+    background: #3c3c3c; color: #ddd;
+    border: 1px solid #3c3c3c; border-radius: 2px;
+    font-family: inherit; font-size: 13px;
+  }
+  input[type=text]:focus, input[type=date]:focus, select:focus, textarea:focus {
+    outline: 1px solid #007fd4; border-color: #007fd4;
+  }
+  button {
+    background: #0e639c; color: #fff;
+    border: none; padding: 6px 14px; border-radius: 2px; cursor: pointer; font-size: 13px;
+  }
+  button:hover { background: #1177bb; }
+  button.secondary { background: #3a3d41; color: #ddd; }
+  button.secondary:hover { background: #45494e; }
+  button:disabled { opacity: 0.5; cursor: not-allowed; }
+  .err { color: #f48771; white-space: pre-wrap; }
+  .ok { color: #89d185; }
+  .hint { font-size: 12px; opacity: 0.7; }
+`
+
+type navItem struct{ Path, Label string }
+
+var navItems = []navItem{
+	{"/", "Home"},
+	{"/plec", "PLEC Upload"},
+	{"/applovin", "AppLovin Upload"},
+	{"/base64", "Base64 Scanner"},
+	{"/daily", "Daily Update"},
+	{"/mobile", "Send To Mobile"},
+}
+
+func Page(activePath, title, body string) string {
+	var tabs strings.Builder
+	for _, n := range navItems {
+		cls := ""
+		if n.Path == activePath {
+			cls = " class=\"active\""
+		}
+		tabs.WriteString(`<a href="` + n.Path + `"` + cls + `>` + n.Label + `</a>`)
+	}
+	return `<!DOCTYPE html>
+<html><head>
+<meta charset="UTF-8" />
+<title>` + title + ` — HPL Toolbox</title>
+<style>` + SharedCSS + `</style>
+</head><body>
+<div class="topbar">` + tabs.String() + `</div>
+<div class="content">` + body + `</div>
+</body></html>`
+}
--- a/standalone/main.go
+++ b/standalone/main.go
@@ -0,0 +1,171 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"syscall"
+	"time"
+	"unsafe"
+
+	webview "github.com/jchv/go-webview2"
+)
+
+var currentHwnd atomic.Uintptr
+
+func setupFileLogging() {
+	logPath := filepath.Join(appDir(), "debug.log")
+	f, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		return
+	}
+	log.SetOutput(f)
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+}
+
+func main() {
+	setupFileLogging()
+	log.Printf("HPL Toolbox starting (pid=%d)", os.Getpid())
+
+	if focusExistingInstance() {
+		log.Printf("Another instance is running; focused it and exiting.")
+		return
+	}
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		log.Fatal(err)
+	}
+	port := listener.Addr().(*net.TCPAddr).Port
+	log.Printf("Server listening on 127.0.0.1:%d", port)
+
+	mux := buildMux()
+	srv := &http.Server{Handler: mux}
+	go func() {
+		if err := srv.Serve(listener); err != nil && err != http.ErrServerClosed {
+			log.Printf("Server error: %v", err)
+		}
+	}()
+
+	if err := writeLockFile(port); err != nil {
+		log.Printf("Failed to write lock file: %v", err)
+	}
+	defer removeLockFile()
+
+	w := webview.NewWithOptions(webview.WebViewOptions{
+		Debug:     false,
+		AutoFocus: true,
+		WindowOptions: webview.WindowOptions{
+			Title:  "HPL Toolbox",
+			Width:  1100,
+			Height: 720,
+			IconId: 1,
+			Center: true,
+		},
+	})
+	if w == nil {
+		log.Fatalln("Failed to create webview.")
+	}
+	defer w.Destroy()
+
+	// Stash HWND for the /api/focus handler.
+	currentHwnd.Store(uintptr(w.Window()))
+
+	w.SetSize(1100, 720, webview.HintNone)
+	w.Navigate(fmt.Sprintf("http://127.0.0.1:%d/", port))
+	w.Run()
+
+	// Window closed — shut the server down cleanly.
+	log.Printf("Window closed; shutting down server.")
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	_ = srv.Shutdown(ctx)
+}
+
+func buildMux() *http.ServeMux {
+	mux := http.NewServeMux()
+
+	// Pages
+	mux.HandleFunc("GET /", func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/" && r.URL.Path != "/home" {
+			http.NotFound(w, r)
+			return
+		}
+		HomePage(w, r)
+	})
+	mux.HandleFunc("GET /plec", PlecPage)
+	mux.HandleFunc("GET /applovin", ApplovinPage)
+	mux.HandleFunc("GET /base64", Base64Page)
+	mux.HandleFunc("GET /daily", DailyPage)
+	mux.HandleFunc("GET /mobile", MobilePage)
+	mux.HandleFunc("GET /assets/qrcode.min.js", MobileQrScript)
+
+	// Shared API
+	mux.HandleFunc("POST /api/clipboard", ClipboardEndpoint)
+	mux.HandleFunc("POST /api/open", OpenEndpoint)
+	mux.HandleFunc("POST /api/focus", FocusEndpoint)
+
+	// Daily Update
+	mux.HandleFunc("POST /api/daily/submit", DailySubmit)
+
+	// PLEC
+	mux.HandleFunc("POST /api/plec/pick", PlecPick)
+	mux.HandleFunc("POST /api/plec/upload", PlecUpload)
+
+	// AppLovin
+	mux.HandleFunc("POST /api/applovin/pick", ApplovinPick)
+	mux.HandleFunc("POST /api/applovin/upload", ApplovinUpload)
+
+	// Base64
+	mux.HandleFunc("POST /api/base64/pickFolder", Base64PickFolder)
+	mux.HandleFunc("POST /api/base64/pickFiles", Base64PickFiles)
+	mux.HandleFunc("POST /api/base64/scan", Base64Scan)
+
+	// Send To Mobile
+	mux.HandleFunc("POST /api/mobile/pick", MobilePick)
+	mux.HandleFunc("POST /api/mobile/start", MobileStart)
+	mux.HandleFunc("POST /api/mobile/stop", MobileStop)
+
+	return mux
+}
+
+// FocusEndpoint brings the webview window to the foreground. Used by a second
+// instance that wants to focus the running one before exiting.
+func FocusEndpoint(w http.ResponseWriter, r *http.Request) {
+	hwnd := currentHwnd.Load()
+	if hwnd != 0 {
+		restoreAndFocus(hwnd)
+	}
+	w.WriteHeader(http.StatusOK)
+}
+
+var (
+	user32              = syscall.NewLazyDLL("user32.dll")
+	procShowWindow      = user32.NewProc("ShowWindow")
+	procSetForeground   = user32.NewProc("SetForegroundWindow")
+	procIsIconic        = user32.NewProc("IsIconic")
+)
+
+const (
+	swRestore = 9
+	swShow    = 5
+)
+
+func restoreAndFocus(hwnd uintptr) {
+	// If minimized, restore. Otherwise just ensure it's shown.
+	iconic, _, _ := procIsIconic.Call(hwnd)
+	if iconic != 0 {
+		_, _, _ = procShowWindow.Call(hwnd, swRestore)
+	} else {
+		_, _, _ = procShowWindow.Call(hwnd, swShow)
+	}
+	_, _, _ = procSetForeground.Call(hwnd)
+}
+
+// Silence "imported and not used" complaints if any.
+var _ = unsafe.Sizeof(int(0))
--- a/standalone/mobile.go
+++ b/standalone/mobile.go
@@ -0,0 +1,390 @@
+package main
+
+import (
+	"context"
+	_ "embed"
+	"encoding/base64"
+	"encoding/json"
+	"crypto/rand"
+	"fmt"
+	"html"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+//go:embed assets/qrcode.min.js
+var qrcodeJS []byte
+
+type activeShare struct {
+	server   *http.Server
+	listener net.Listener
+	port     int
+	token    string
+	fileBuf  []byte
+	filename string
+}
+
+var (
+	activeMu sync.Mutex
+	active   *activeShare
+)
+
+func stopActiveShare() {
+	activeMu.Lock()
+	defer activeMu.Unlock()
+	if active != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+		_ = active.server.Shutdown(ctx)
+		active = nil
+	}
+}
+
+func MobileQrScript(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/javascript; charset=utf-8")
+	_, _ = w.Write(qrcodeJS)
+}
+
+func MobilePage(w http.ResponseWriter, r *http.Request) {
+	body := `
+<h2>Send To Mobile</h2>
+<p class="hint" style="margin-top:0;">
+  Pick an HTML file, then start sharing. Scan the QR with a phone on the same WiFi.
+  The phone gets a choice of <strong>View</strong> or <strong>Download</strong>.
+</p>
+
+<div style="margin-bottom:14px;">
+  <div style="display:flex;align-items:center;gap:8px;">
+    <button id="pick" class="secondary">Choose...</button>
+    <span id="fileName" class="hint">(no file)</span>
+  </div>
+  <input type="hidden" id="filePath" />
+</div>
+
+<div style="margin-bottom:14px;">
+  <button id="start">Start sharing</button>
+  <button id="stop" class="secondary" disabled>Stop</button>
+</div>
+
+<div id="ifaceWrap" style="display:none;margin-bottom:14px;">
+  <div class="hint">Multiple network interfaces found. Pick the one your phone can reach:</div>
+  <div id="ifaceList" style="display:flex;flex-direction:column;gap:4px;margin-top:6px;"></div>
+</div>
+
+<div id="shareInfo" style="display:none;">
+  <div id="qr" style="margin-top:14px;background:#fff;padding:12px;display:inline-block;border-radius:4px;"></div>
+  <div class="url" id="urlText" style="margin-top:10px;padding:8px;background:#252526;border-left:3px solid #007fd4;font-family:Consolas, monospace;font-size:12px;word-break:break-all;"></div>
+  <div style="margin-top:6px;display:flex;gap:6px;">
+    <button id="copyUrl" class="secondary">Copy URL</button>
+    <button id="openUrl" class="secondary">Open in browser</button>
+  </div>
+  <div class="hint" style="margin-top:8px;">
+    First run on Windows may show a firewall prompt — allow access for "Private networks".
+  </div>
+</div>
+
+<div id="status" style="margin-top:12px;min-height:18px;"></div>
+
+<script src="/assets/qrcode.min.js"></script>
+<script>
+const pickBtn = document.getElementById('pick');
+const startBtn = document.getElementById('start');
+const stopBtn = document.getElementById('stop');
+const fileNameEl = document.getElementById('fileName');
+const filePathEl = document.getElementById('filePath');
+const statusEl = document.getElementById('status');
+const shareInfo = document.getElementById('shareInfo');
+const ifaceWrap = document.getElementById('ifaceWrap');
+const ifaceList = document.getElementById('ifaceList');
+const qrEl = document.getElementById('qr');
+const urlTextEl = document.getElementById('urlText');
+
+let currentUrls = [];
+let selectedIdx = 0;
+
+pickBtn.addEventListener('click', async () => {
+  const r = await fetch('/api/mobile/pick', { method:'POST' });
+  const j = await r.json();
+  if (j.path) {
+    filePathEl.value = j.path;
+    fileNameEl.textContent = j.name;
+  }
+});
+
+startBtn.addEventListener('click', async () => {
+  statusEl.innerHTML = '';
+  if (!filePathEl.value) {
+    statusEl.innerHTML = '<span class="err">Pick an HTML file first.</span>';
+    return;
+  }
+  startBtn.disabled = true;
+  statusEl.textContent = 'Starting server...';
+  const r = await fetch('/api/mobile/start', {
+    method:'POST', headers:{'Content-Type':'application/json'},
+    body: JSON.stringify({ path: filePathEl.value }),
+  });
+  const j = await r.json();
+  if (j.error) {
+    statusEl.innerHTML = '<span class="err">' + j.error + '</span>';
+    startBtn.disabled = false;
+    return;
+  }
+  currentUrls = j.urls;
+  selectedIdx = 0;
+  statusEl.innerHTML = '<span class="ok">Sharing: ' + j.filename + '</span>';
+  shareInfo.style.display = '';
+  renderIfaces(j.urls);
+  renderQr(j.urls[0].url);
+  stopBtn.disabled = false;
+});
+
+stopBtn.addEventListener('click', async () => {
+  await fetch('/api/mobile/stop', { method:'POST' });
+  statusEl.textContent = 'Stopped.';
+  shareInfo.style.display = 'none';
+  currentUrls = [];
+  startBtn.disabled = false;
+  stopBtn.disabled = true;
+});
+
+document.getElementById('copyUrl').addEventListener('click', () => {
+  const url = currentUrls[selectedIdx]?.url || '';
+  fetch('/api/clipboard', {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({text:url})});
+});
+document.getElementById('openUrl').addEventListener('click', () => {
+  const url = currentUrls[selectedIdx]?.url || '';
+  fetch('/api/open', {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({url})});
+});
+
+function renderQr(url) {
+  qrEl.innerHTML = '';
+  urlTextEl.textContent = url;
+  try {
+    const qr = qrcode(0, 'M');
+    qr.addData(url);
+    qr.make();
+    qrEl.innerHTML = qr.createSvgTag({ cellSize: 5, margin: 2, scalable: true });
+    const svg = qrEl.querySelector('svg');
+    if (svg) { svg.setAttribute('width','240'); svg.setAttribute('height','240'); }
+  } catch (e) {
+    qrEl.textContent = 'QR render failed: ' + e.message;
+  }
+}
+
+function renderIfaces(urls) {
+  ifaceList.innerHTML = '';
+  if (urls.length <= 1) { ifaceWrap.style.display = 'none'; return; }
+  ifaceWrap.style.display = '';
+  urls.forEach((u, i) => {
+    const id = 'iface_' + i;
+    const label = document.createElement('label');
+    label.style.fontSize = '12px';
+    label.style.cursor = 'pointer';
+    label.innerHTML = '<input type="radio" name="iface" id="' + id + '"' +
+      (i === selectedIdx ? ' checked' : '') + ' /> ' +
+      u.ip + ' <span style="opacity:0.6;">(' + u.iface + ')</span>';
+    label.querySelector('input').addEventListener('change', () => {
+      selectedIdx = i;
+      renderQr(urls[i].url);
+    });
+    ifaceList.appendChild(label);
+  });
+}
+</script>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/mobile", "Send To Mobile", body)))
+}
+
+func MobilePick(w http.ResponseWriter, r *http.Request) {
+	picked := PickFiles(
+		"Select HTML",
+		[]FileFilter{{Name: "HTML", Extensions: []string{"html", "htm"}}},
+		false, "",
+	)
+	if len(picked) == 0 {
+		writeJSON(w, map[string]any{"path": nil})
+		return
+	}
+	writeJSON(w, map[string]any{"path": picked[0], "name": filepath.Base(picked[0])})
+}
+
+func MobileStart(w http.ResponseWriter, r *http.Request) {
+	stopActiveShare()
+
+	var req struct {
+		Path string `json:"path"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"error": err.Error()})
+		return
+	}
+	if req.Path == "" || !fileExists(req.Path) {
+		writeJSON(w, map[string]any{"error": "File missing."})
+		return
+	}
+	fileBuf, err := os.ReadFile(req.Path)
+	if err != nil {
+		writeJSON(w, map[string]any{"error": "Read failed: " + err.Error()})
+		return
+	}
+	filename := filepath.Base(req.Path)
+
+	// 6 random bytes -> base64url, no padding
+	tokenBytes := make([]byte, 6)
+	if _, err := rand.Read(tokenBytes); err != nil {
+		writeJSON(w, map[string]any{"error": "Token gen failed: " + err.Error()})
+		return
+	}
+	token := strings.TrimRight(base64.URLEncoding.EncodeToString(tokenBytes), "=")
+
+	cfgPort := LoadConfig().SendToMobile.Port
+	listener, err := net.Listen("tcp", "0.0.0.0:"+strconv.Itoa(cfgPort))
+	if err != nil {
+		writeJSON(w, map[string]any{"error": "Failed to bind: " + err.Error()})
+		return
+	}
+	port := listener.Addr().(*net.TCPAddr).Port
+
+	share := &activeShare{
+		listener: listener,
+		port:     port,
+		token:    token,
+		fileBuf:  fileBuf,
+		filename: filename,
+	}
+	share.server = &http.Server{Handler: shareHandler(share)}
+
+	go func() { _ = share.server.Serve(listener) }()
+
+	ips := getLanIPs()
+	if len(ips) == 0 {
+		_ = share.server.Close()
+		writeJSON(w, map[string]any{"error": "No non-loopback IPv4 interface found. Are you on a network?"})
+		return
+	}
+
+	activeMu.Lock()
+	active = share
+	activeMu.Unlock()
+
+	type urlInfo struct {
+		IP    string `json:"ip"`
+		Iface string `json:"iface"`
+		URL   string `json:"url"`
+	}
+	urls := make([]urlInfo, 0, len(ips))
+	for _, ip := range ips {
+		urls = append(urls, urlInfo{
+			IP:    ip.address,
+			Iface: ip.iface,
+			URL:   fmt.Sprintf("http://%s:%d/s/%s/", ip.address, port, token),
+		})
+	}
+	writeJSON(w, map[string]any{"urls": urls, "filename": filename})
+}
+
+func MobileStop(w http.ResponseWriter, r *http.Request) {
+	stopActiveShare()
+	writeJSON(w, map[string]any{"ok": true})
+}
+
+func shareHandler(s *activeShare) http.Handler {
+	prefix := "/s/" + s.token
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet || !strings.HasPrefix(r.URL.Path, prefix) {
+			http.NotFound(w, r)
+			return
+		}
+		rest := strings.TrimPrefix(r.URL.Path, prefix)
+		switch rest {
+		case "", "/":
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.Header().Set("Cache-Control", "no-store")
+			_, _ = w.Write([]byte(chooserPage(s.filename)))
+		case "/view":
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			w.Header().Set("Cache-Control", "no-store")
+			_, _ = w.Write(s.fileBuf)
+		case "/file":
+			safeName := safeFilename(s.filename)
+			w.Header().Set("Content-Type", "application/octet-stream")
+			w.Header().Set("Content-Disposition", `attachment; filename="`+safeName+`"`)
+			w.Header().Set("Content-Length", strconv.Itoa(len(s.fileBuf)))
+			w.Header().Set("Cache-Control", "no-store")
+			_, _ = w.Write(s.fileBuf)
+		default:
+			http.NotFound(w, r)
+		}
+	})
+}
+
+var unsafeFilenameRx = regexp.MustCompile(`[^A-Za-z0-9._-]`)
+
+func safeFilename(s string) string { return unsafeFilenameRx.ReplaceAllString(s, "_") }
+
+func chooserPage(filename string) string {
+	escName := html.EscapeString(filename)
+	return `<!DOCTYPE html>
+<html><head>
+<meta charset="UTF-8" />
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+<title>Send To Mobile</title>
+<style>
+  body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+         margin: 0; padding: 24px; background: #111; color: #eee; }
+  h1 { font-size: 18px; font-weight: 500; margin: 0 0 4px; opacity: 0.85; }
+  .file { font-size: 13px; opacity: 0.6; margin-bottom: 28px; word-break: break-all; }
+  a.btn { display: block; padding: 18px; margin-bottom: 14px; border-radius: 10px;
+          font-size: 17px; font-weight: 500; text-align: center; text-decoration: none; }
+  a.view { background: #2d7dff; color: white; }
+  a.dl { background: #2a2a2a; color: #eee; border: 1px solid #3a3a3a; }
+</style></head>
+<body>
+  <h1>HPL Toolbox</h1>
+  <div class="file">` + escName + `</div>
+  <a class="btn view" href="view">View in browser</a>
+  <a class="btn dl" href="file" download="` + escName + `">Download .html</a>
+</body></html>`
+}
+
+type lanIP struct {
+	address string
+	iface   string
+}
+
+func getLanIPs() []lanIP {
+	var out []lanIP
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return out
+	}
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 || iface.Flags&net.FlagLoopback != 0 {
+			continue
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+		for _, a := range addrs {
+			ipNet, ok := a.(*net.IPNet)
+			if !ok {
+				continue
+			}
+			ip4 := ipNet.IP.To4()
+			if ip4 == nil || ip4.IsLoopback() {
+				continue
+			}
+			out = append(out, lanIP{address: ip4.String(), iface: iface.Name})
+		}
+	}
+	return out
+}
--- a/standalone/platform.go
+++ b/standalone/platform.go
@@ -0,0 +1,177 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+type PlecConfig struct {
+	UploadUrl       string `json:"uploadUrl"`
+	OriginUrl       string `json:"originUrl"`
+	PreviewBase     string `json:"previewBase"`
+	SkipExistsCheck bool   `json:"skipExistsCheck"`
+}
+
+type ApplovinConfig struct {
+	Cookie string `json:"cookie"`
+}
+
+type SendToMobileConfig struct {
+	Port int `json:"port"`
+}
+
+type DailyUpdateConfig struct {
+	LastProject string `json:"lastProject"`
+}
+
+type AppConfig struct {
+	Plec         PlecConfig         `json:"plec"`
+	Applovin     ApplovinConfig     `json:"applovin"`
+	SendToMobile SendToMobileConfig `json:"sendToMobile"`
+	DailyUpdate  DailyUpdateConfig  `json:"dailyUpdate"`
+}
+
+var configMu sync.Mutex
+
+func defaultConfig() AppConfig {
+	return AppConfig{
+		Plec: PlecConfig{
+			UploadUrl:       "http://167.99.227.249/src/upload_HTML_Experimental.php",
+			OriginUrl:       "http://167.99.227.249",
+			PreviewBase:     "https://playable.applovindemo.com/phaser/",
+			SkipExistsCheck: false,
+		},
+		Applovin:     ApplovinConfig{Cookie: ""},
+		SendToMobile: SendToMobileConfig{Port: 0},
+		DailyUpdate:  DailyUpdateConfig{LastProject: ""},
+	}
+}
+
+func appDir() string {
+	exe, err := os.Executable()
+	if err != nil {
+		wd, _ := os.Getwd()
+		return wd
+	}
+	// `go run` puts the exe in a temp dir; fall back to cwd in that case.
+	resolved, err := filepath.EvalSymlinks(exe)
+	if err == nil {
+		exe = resolved
+	}
+	dir := filepath.Dir(exe)
+	if strings.Contains(strings.ToLower(dir), "go-build") {
+		wd, _ := os.Getwd()
+		return wd
+	}
+	return dir
+}
+
+func configPath() string {
+	return filepath.Join(appDir(), "config.json")
+}
+
+func LoadConfig() AppConfig {
+	configMu.Lock()
+	defer configMu.Unlock()
+	cfg := defaultConfig()
+	data, err := os.ReadFile(configPath())
+	if err != nil {
+		return cfg
+	}
+	_ = json.Unmarshal(data, &cfg)
+	return cfg
+}
+
+func SaveConfig(cfg AppConfig) error {
+	configMu.Lock()
+	defer configMu.Unlock()
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(configPath(), data, 0644)
+}
+
+func OpenInBrowser(url string) {
+	// `start` is a cmd builtin. Quoted empty arg is the window title.
+	cmd := exec.Command("cmd", "/c", "start", "", url)
+	_ = cmd.Start()
+}
+
+func CopyToClipboard(text string) error {
+	cmd := exec.Command("clip")
+	cmd.Stdin = strings.NewReader(text)
+	return cmd.Run()
+}
+
+type FileFilter struct {
+	Name       string
+	Extensions []string
+}
+
+func psEscape(s string) string { return strings.ReplaceAll(s, "'", "''") }
+
+func PickFiles(title string, filters []FileFilter, multi bool, initialDir string) []string {
+	filterStr := "All files|*.*"
+	if len(filters) > 0 {
+		parts := make([]string, 0, len(filters))
+		for _, f := range filters {
+			exts := make([]string, 0, len(f.Extensions))
+			for _, e := range f.Extensions {
+				exts = append(exts, "*."+e)
+			}
+			parts = append(parts, fmt.Sprintf("%s|%s", f.Name, strings.Join(exts, ";")))
+		}
+		filterStr = strings.Join(parts, "|")
+	}
+	multiStr := "false"
+	if multi {
+		multiStr = "true"
+	}
+	script := fmt.Sprintf(`
+Add-Type -AssemblyName System.Windows.Forms
+$dlg = New-Object System.Windows.Forms.OpenFileDialog
+$dlg.Title = '%s'
+$dlg.Filter = '%s'
+$dlg.Multiselect = $%s
+if ('%s'.Length -gt 0) { $dlg.InitialDirectory = '%s' }
+if ($dlg.ShowDialog() -eq [System.Windows.Forms.DialogResult]::OK) {
+  $dlg.FileNames | ForEach-Object { Write-Output $_ }
+}
+`, psEscape(title), psEscape(filterStr), multiStr, psEscape(initialDir), psEscape(initialDir))
+	out, err := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-STA", "-Command", script).Output()
+	if err != nil {
+		return nil
+	}
+	lines := strings.Split(string(out), "\n")
+	result := make([]string, 0, len(lines))
+	for _, l := range lines {
+		t := strings.TrimSpace(l)
+		if t != "" {
+			result = append(result, t)
+		}
+	}
+	return result
+}
+
+func PickFolder(title, initialDir string) string {
+	script := fmt.Sprintf(`
+Add-Type -AssemblyName System.Windows.Forms
+$dlg = New-Object System.Windows.Forms.FolderBrowserDialog
+$dlg.Description = '%s'
+if ('%s'.Length -gt 0) { $dlg.SelectedPath = '%s' }
+if ($dlg.ShowDialog() -eq [System.Windows.Forms.DialogResult]::OK) {
+  Write-Output $dlg.SelectedPath
+}
+`, psEscape(title), psEscape(initialDir), psEscape(initialDir))
+	out, err := exec.Command("powershell", "-NoProfile", "-NonInteractive", "-STA", "-Command", script).Output()
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(out))
+}
--- a/standalone/plec.go
+++ b/standalone/plec.go
@@ -0,0 +1,376 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	urlpkg "net/url"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"time"
+)
+
+func PlecPage(w http.ResponseWriter, r *http.Request) {
+	body := `
+<h2>PLEC Upload</h2>
+<p class="hint" style="margin-top:0;">Pick HTML files, give each an iteration name, then upload. The preview link is returned by the server.</p>
+
+<table id="rows" style="width:100%;border-collapse:collapse;margin-bottom:12px;">
+  <thead><tr>
+    <th style="width:45%;text-align:left;padding:6px 8px;font-size:12px;text-transform:uppercase;opacity:0.7;">HTML File</th>
+    <th style="width:45%;text-align:left;padding:6px 8px;font-size:12px;text-transform:uppercase;opacity:0.7;">Iteration Name</th>
+    <th></th>
+  </tr></thead>
+  <tbody></tbody>
+</table>
+
+<div style="display:flex;gap:8px;">
+  <button id="addRow" class="secondary">+ Add Row</button>
+  <button id="upload">Upload</button>
+</div>
+
+<div id="status" style="margin-top:12px;min-height:20px;"></div>
+<div id="results"></div>
+
+<style>
+  #rows td { padding:6px 8px; vertical-align:middle; border-bottom:1px solid #333; }
+  .file-cell { display:flex; align-items:center; gap:8px; }
+  .file-name { opacity:0.85; font-size:12px; word-break:break-all; }
+  .row-error { color:#f48771; font-size:12px; margin-top:4px; }
+  .result { margin-top:12px; padding:10px; background:#252526; border-left:3px solid #007fd4; word-break:break-all; }
+  .result a { color:#9cdcfe; }
+  .result-actions { margin-top:8px; display:flex; gap:8px; }
+  .remove-btn { background:transparent; color:#ddd; padding:4px 8px; }
+</style>
+
+<script>
+let nextId = 1;
+const tbody = document.querySelector('#rows tbody');
+const statusEl = document.getElementById('status');
+const resultsEl = document.getElementById('results');
+
+function addRow() {
+  const id = 'r' + (nextId++);
+  const tr = document.createElement('tr');
+  tr.dataset.id = id;
+  tr.innerHTML = ` + "`" + `
+    <td>
+      <div class="file-cell">
+        <button class="pick secondary">Choose...</button>
+        <span class="file-name" data-name>(no file)</span>
+      </div>
+      <input type="hidden" data-path />
+      <div class="row-error" data-error></div>
+    </td>
+    <td><input type="text" data-iter placeholder="iteration name" style="width:100%;" /></td>
+    <td><button class="remove-btn" title="Remove">×</button></td>
+  ` + "`" + `;
+  tr.querySelector('.pick').addEventListener('click', async () => {
+    const res = await fetch('/api/plec/pick', { method: 'POST' });
+    const j = await res.json();
+    if (j.path) {
+      tr.querySelector('[data-path]').value = j.path;
+      tr.querySelector('[data-name]').textContent = j.name;
+      const iter = tr.querySelector('[data-iter]');
+      if (!iter.value) iter.value = j.name.replace(/\.html?$/i, '');
+    }
+  });
+  tr.querySelector('.remove-btn').addEventListener('click', () => {
+    tr.remove();
+    if (!tbody.children.length) addRow();
+  });
+  tbody.appendChild(tr);
+}
+
+document.getElementById('addRow').addEventListener('click', addRow);
+
+document.getElementById('upload').addEventListener('click', async () => {
+  document.querySelectorAll('[data-error]').forEach(el => el.textContent = '');
+  statusEl.textContent = '';
+  resultsEl.innerHTML = '';
+  const rows = [...tbody.querySelectorAll('tr')].map(tr => ({
+    id: tr.dataset.id,
+    path: tr.querySelector('[data-path]').value,
+    iteration: tr.querySelector('[data-iter]').value,
+  })).filter(r => r.path || r.iteration);
+  if (rows.length === 0) {
+    statusEl.innerHTML = '<span class="err">Add at least one row with a file and iteration name.</span>';
+    return;
+  }
+  statusEl.textContent = 'Uploading...';
+  const res = await fetch('/api/plec/upload', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ rows }),
+  });
+  const j = await res.json();
+  if (j.rowErrors) {
+    for (const re of j.rowErrors) {
+      const tr = tbody.querySelector('tr[data-id="' + re.id + '"]');
+      if (tr) tr.querySelector('[data-error]').textContent = re.message;
+    }
+    statusEl.innerHTML = '<span class="err">Fix row errors and retry.</span>';
+    return;
+  }
+  if (j.error) {
+    statusEl.innerHTML = '<span class="err">' + j.error + '</span>';
+    return;
+  }
+  statusEl.innerHTML = '<span class="ok">Upload complete.</span>';
+  const wrap = document.createElement('div');
+  wrap.className = 'result';
+  if (j.preview) {
+    wrap.innerHTML = '<div><strong>Preview:</strong> <a href="' + j.preview + '" target="_blank">' + j.preview + '</a></div>';
+    const actions = document.createElement('div');
+    actions.className = 'result-actions';
+    const copy = document.createElement('button');
+    copy.textContent = 'Copy';
+    copy.onclick = () => fetch('/api/clipboard', { method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify({ text: j.preview }) });
+    const open = document.createElement('button');
+    open.textContent = 'Open';
+    open.className = 'secondary';
+    open.onclick = () => fetch('/api/open', { method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify({ url: j.preview }) });
+    const showRaw = document.createElement('button');
+    showRaw.textContent = 'Show server response';
+    showRaw.className = 'secondary';
+    showRaw.onclick = () => {
+      const pre = document.createElement('pre');
+      pre.style.marginTop = '8px';
+      pre.style.whiteSpace = 'pre-wrap';
+      pre.textContent = j.rawText;
+      wrap.appendChild(pre);
+      showRaw.disabled = true;
+    };
+    actions.appendChild(copy); actions.appendChild(open); actions.appendChild(showRaw);
+    wrap.appendChild(actions);
+  } else {
+    wrap.innerHTML = '<div>No preview field in response. Raw:</div><pre>' + (j.rawText || '').replace(/</g,'&lt;') + '</pre>';
+  }
+  resultsEl.innerHTML = '';
+  resultsEl.appendChild(wrap);
+});
+
+addRow();
+</script>
+`
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write([]byte(Page("/plec", "PLEC Upload", body)))
+}
+
+func PlecPick(w http.ResponseWriter, r *http.Request) {
+	picked := PickFiles(
+		"Select HTML",
+		[]FileFilter{{Name: "HTML", Extensions: []string{"html", "htm"}}},
+		false, "",
+	)
+	if len(picked) == 0 {
+		writeJSON(w, map[string]any{"path": nil})
+		return
+	}
+	writeJSON(w, map[string]any{"path": picked[0], "name": filepath.Base(picked[0])})
+}
+
+type plecRow struct {
+	ID        string `json:"id"`
+	Path      string `json:"path"`
+	Iteration string `json:"iteration"`
+}
+
+func PlecUpload(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Rows []plecRow `json:"rows"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"error": err.Error()})
+		return
+	}
+	cfg := LoadConfig().Plec
+
+	type rowErr struct {
+		ID      string `json:"id"`
+		Message string `json:"message"`
+	}
+	var rowErrors []rowErr
+	var valid []plecRow
+	htmlRx := regexp.MustCompile(`(?i)\.html?$`)
+
+	for _, row := range req.Rows {
+		if row.Path == "" || !fileExists(row.Path) {
+			rowErrors = append(rowErrors, rowErr{row.ID, "File missing"})
+		} else if strings.TrimSpace(row.Iteration) == "" {
+			rowErrors = append(rowErrors, rowErr{row.ID, "Iteration name required"})
+		} else if !htmlRx.MatchString(row.Path) {
+			rowErrors = append(rowErrors, rowErr{row.ID, "Must be .html"})
+		} else {
+			valid = append(valid, row)
+		}
+	}
+	if len(rowErrors) > 0 {
+		writeJSON(w, map[string]any{"rowErrors": rowErrors})
+		return
+	}
+	if len(valid) == 0 {
+		writeJSON(w, map[string]any{"error": "Nothing to upload."})
+		return
+	}
+
+	stamp := time.Now().Format("20060102150405")
+
+	var buf bytes.Buffer
+	mw := multipart.NewWriter(&buf)
+	for i, row := range valid {
+		idx := i + 1
+		data, err := os.ReadFile(row.Path)
+		if err != nil {
+			writeJSON(w, map[string]any{"error": "Read failed: " + err.Error()})
+			return
+		}
+		stampedName := appendTimestamp(filepath.Base(row.Path), stamp)
+		fw, err := createFormFileWithType(mw, fmt.Sprintf("fileUpload_%d", idx), stampedName, "text/html")
+		if err != nil {
+			writeJSON(w, map[string]any{"error": err.Error()})
+			return
+		}
+		if _, err := fw.Write(data); err != nil {
+			writeJSON(w, map[string]any{"error": err.Error()})
+			return
+		}
+		iter := urlpkg.QueryEscape(strings.ReplaceAll(row.Iteration, " ", ""))
+		// Original uses encodeURI which keeps more chars than QueryEscape; emulate by un-escaping safe chars.
+		iter = encodeURICompatible(strings.ReplaceAll(row.Iteration, " ", ""))
+		if err := mw.WriteField(fmt.Sprintf("iterationNameUpload_%d", idx), iter); err != nil {
+			writeJSON(w, map[string]any{"error": err.Error()})
+			return
+		}
+	}
+	if err := mw.Close(); err != nil {
+		writeJSON(w, map[string]any{"error": err.Error()})
+		return
+	}
+
+	httpReq, err := http.NewRequest("POST", cfg.UploadUrl, &buf)
+	if err != nil {
+		writeJSON(w, map[string]any{"error": err.Error()})
+		return
+	}
+	httpReq.Header.Set("Content-Type", mw.FormDataContentType())
+	httpReq.Header.Set("Origin", cfg.OriginUrl)
+	httpReq.Header.Set("Referer", cfg.OriginUrl+"/")
+	httpReq.Header.Set("User-Agent", "Mozilla/5.0 (HPL-Toolbox-Standalone)")
+	httpReq.Header.Set("X-Requested-With", "XMLHttpRequest")
+	httpReq.Header.Set("Accept", "*/*")
+
+	resp, err := http.DefaultClient.Do(httpReq)
+	if err != nil {
+		writeJSON(w, map[string]any{"error": "Network error: " + err.Error()})
+		return
+	}
+	defer resp.Body.Close()
+	respBody, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		writeJSON(w, map[string]any{"error": fmt.Sprintf("HTTP %d\n%s", resp.StatusCode, truncate(string(respBody), 800))})
+		return
+	}
+	var parsed map[string]any
+	if err := json.Unmarshal(respBody, &parsed); err != nil {
+		writeJSON(w, map[string]any{"error": "Server returned non-JSON:\n" + truncate(string(respBody), 800)})
+		return
+	}
+	var preview any
+	if v, ok := parsed["preview"]; ok && v != nil {
+		preview = v
+	} else if v, ok := parsed["previewURL"]; ok {
+		preview = v
+	}
+	writeJSON(w, map[string]any{"preview": preview, "raw": parsed, "rawText": string(respBody)})
+}
+
+func ClipboardEndpoint(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Text string `json:"text"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	if err := CopyToClipboard(req.Text); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	writeJSON(w, map[string]any{"ok": true})
+}
+
+func OpenEndpoint(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		URL string `json:"url"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	OpenInBrowser(req.URL)
+	writeJSON(w, map[string]any{"ok": true})
+}
+
+func fileExists(p string) bool {
+	_, err := os.Stat(p)
+	return err == nil
+}
+
+func appendTimestamp(filename, stamp string) string {
+	ext := filepath.Ext(filename)
+	base := filename
+	if ext != "" {
+		base = filename[:len(filename)-len(ext)]
+	}
+	return base + "_" + stamp + ext
+}
+
+func truncate(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	return s[:n]
+}
+
+// createFormFileWithType is like multipart.Writer.CreateFormFile but lets us
+// override the Content-Type (CreateFormFile hardcodes "application/octet-stream").
+func createFormFileWithType(mw *multipart.Writer, field, filename, contentType string) (io.Writer, error) {
+	h := make(map[string][]string)
+	h["Content-Disposition"] = []string{
+		fmt.Sprintf(`form-data; name=%q; filename=%q`, field, filename),
+	}
+	h["Content-Type"] = []string{contentType}
+	return mw.CreatePart(h)
+}
+
+// encodeURICompatible mimics JS encodeURI() — keeps A-Za-z0-9 and these
+// reserved/mark chars: ;,/?:@&=+$-_.!~*'()#
+func encodeURICompatible(s string) string {
+	keep := func(c byte) bool {
+		if (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') {
+			return true
+		}
+		switch c {
+		case ';', ',', '/', '?', ':', '@', '&', '=', '+', '$',
+			'-', '_', '.', '!', '~', '*', '\'', '(', ')', '#':
+			return true
+		}
+		return false
+	}
+	var b strings.Builder
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		if keep(c) {
+			b.WriteByte(c)
+		} else {
+			b.WriteString(fmt.Sprintf("%%%02X", c))
+		}
+	}
+	return b.String()
+}
--- a/standalone/rsrc.syso
+++ b/standalone/rsrc.syso
--- a/standalone/single_instance.go
+++ b/standalone/single_instance.go
@@ -0,0 +1,68 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func lockFilePath() string {
+	return filepath.Join(appDir(), ".hpltoolbox.lock")
+}
+
+// focusExistingInstance returns true if another instance was found and
+// successfully asked to focus its window. In that case the caller should exit.
+// Returns false if no live instance exists (and clears any stale lock).
+func focusExistingInstance() bool {
+	data, err := os.ReadFile(lockFilePath())
+	if err != nil {
+		return false
+	}
+	parts := strings.Split(strings.TrimSpace(string(data)), "\n")
+	if len(parts) != 2 {
+		_ = os.Remove(lockFilePath())
+		return false
+	}
+	pid, errPid := strconv.Atoi(strings.TrimSpace(parts[0]))
+	port, errPort := strconv.Atoi(strings.TrimSpace(parts[1]))
+	if errPid != nil || errPort != nil {
+		_ = os.Remove(lockFilePath())
+		return false
+	}
+
+	// Quick liveness check: PID must exist.
+	if proc, err := os.FindProcess(pid); err != nil || proc == nil {
+		_ = os.Remove(lockFilePath())
+		return false
+	}
+
+	// Ask the running instance to focus its window.
+	client := &http.Client{Timeout: 1500 * time.Millisecond}
+	url := fmt.Sprintf("http://127.0.0.1:%d/api/focus", port)
+	resp, err := client.Post(url, "application/json", bytes.NewReader(nil))
+	if err != nil {
+		// Lock file is stale (process died but didn't clean up).
+		_ = os.Remove(lockFilePath())
+		return false
+	}
+	_ = resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		_ = os.Remove(lockFilePath())
+		return false
+	}
+	return true
+}
+
+func writeLockFile(port int) error {
+	content := fmt.Sprintf("%d\n%d\n", os.Getpid(), port)
+	return os.WriteFile(lockFilePath(), []byte(content), 0644)
+}
+
+func removeLockFile() {
+	_ = os.Remove(lockFilePath())
+}