Remove native folder picker, use text input instead

Native OS dialog (zenity/AppleScript/PowerShell) fails on Linux with
"native folder picker is not supported on this platform". Replaced:
- dashboard: removed the "+" button, users type mount path manually
- settings: replaced "Add source folder" native dialog with inline
  text input field

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/templates/dashboard.html

@@ -5,7 +5,6 @@
   <div class="panel-body">
     <div class="path-input-row">
       <input class="form-input" type="text" id="mountPath" placeholder="/Volumes/JUKEBOX or E:\\">
-      <button type="button" class="button-primary" onclick="pickMountPath()">+</button>
       <button type="button" class="button-secondary" onclick="refreshSelectedDisk()">Refresh</button>
     </div>
     <div class="form-hint">Choose the directory where the removable disk is mounted. The app works with one selected disk at a time in standalone mode.</div>
@@ -290,27 +289,6 @@ function startTaskPoll(taskID) {
   pollTask(taskID);
 }
 
-async function pickFolder() {
-  const response = await fetch('/api/system/pick-folder', { method: 'POST' });
-  const payload = await response.json();
-  if (!response.ok) {
-    throw new Error(payload.error || 'Failed to choose folder');
-  }
-  return payload.path || '';
-}
-
-async function pickMountPath() {
-  try {
-    const path = await pickFolder();
-    if (!path) return;
-    document.getElementById('mountPath').value = path;
-    localStorage.setItem('jukebox.selectedMountPath', path);
-    await refreshSelectedDisk();
-  } catch (error) {
-    toast(error.message || 'Failed to choose folder', 'error');
-  }
-}
-
 async function refreshSelectedDisk() {
   const mountPath = document.getElementById('mountPath').value.trim();
   if (!mountPath) {

web/templates/settings.html

@@ -7,7 +7,8 @@
       <div class="form-hint">Add one or more root folders with source files. After that, expand each root and enable or disable individual nested folders with checkboxes.</div>
     </div>
     <div class="btn-row">
-      <button type="button" class="button-primary" onclick="addSourceRoot()">Add source folder</button>
+      <input class="form-input" type="text" id="newSourcePath" placeholder="/media/movies">
+      <button type="button" class="button-primary" onclick="addSourceRoot()">Add</button>
       <button type="button" class="button-secondary button-sm" onclick="reloadAllSourceTrees()">Refresh trees</button>
     </div>
     <div class="source-list">
@@ -36,16 +37,11 @@
         <span class="form-hint">The new-only mode skips files already copied to this disk, even if they were later removed.</span>
       </div>
 
-      <div class="form-group">
-        <label class="form-label" for="allowedFilesMode">Allowed file types</label>
-        <select class="form-select" id="allowedFilesMode" style="width:auto;max-width:420px" onchange="updateAllowedFilesModeUI()">
-          <option value="media_types">Audio, video, photo</option>
-          <option value="extensions">Custom extensions list</option>
-        </select>
-      </div>
-
       <div class="form-group" id="mediaTypesGroup">
-        <label class="form-label">Built-in media types</label>
+        <div style="display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap">
+          <label class="form-label" style="margin:0">Allowed file types</label>
+          <button type="button" class="button-secondary button-sm" id="editAllowedFilesButton" onclick="toggleAllowedFilesEditor()">Edit list</button>
+        </div>
         <div style="display:grid;gap:8px">
           <label style="display:flex;align-items:flex-start;gap:8px;cursor:pointer">
             <input type="checkbox" id="mediaTypeAudio" style="width:15px;height:15px;accent-color:var(--accent)">
@@ -73,7 +69,10 @@
       </div>
 
       <div class="form-group" id="extensionsGroup" style="display:none">
-        <label class="form-label" for="allowedExtensions">Allowed extensions</label>
+        <div style="display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap">
+          <label class="form-label" for="allowedExtensions" style="margin:0">Allowed extensions</label>
+          <button type="button" class="button-secondary button-sm" onclick="toggleAllowedFilesEditor()">Use media types</button>
+        </div>
         <textarea class="form-input" id="allowedExtensions" rows="5" placeholder=".mp3, .flac, .mp4"></textarea>
         <span class="form-hint">One extension per line or separated by commas. You can write <code>mp3</code> or <code>.mp3</code>.</span>
       </div>
@@ -127,6 +126,7 @@ const builtInMediaTypes = {
 };
 let sourceRoots = [];
 let sourceConfig = {};
+let allowedFilesMode = 'media_types';
 
 function escapeHTML(value) {
   return String(value || '').replace(/[&<>"']/g, (char) => ({
@@ -206,15 +206,6 @@ function collectSourcesForSave() {
   return items.sort((a, b) => a.path.localeCompare(b.path));
 }
 
-async function pickFolder() {
-  const response = await fetch('/api/system/pick-folder', { method: 'POST' });
-  const payload = await response.json();
-  if (!response.ok) {
-    throw new Error(payload.error || 'Failed to choose folder');
-  }
-  return payload.path || '';
-}
-
 async function loadSourceChildren(path) {
   if (!path || loadingNodes.has(path)) return;
   loadingNodes.add(path);
@@ -262,21 +253,19 @@ function removeRoot(path) {
 }
 
 async function addSourceRoot() {
-  try {
-    const path = await pickFolder();
-    if (!path) return;
-    if (sourceRoots.some((root) => isSamePath(root, path))) {
-      toast('This source folder is already added', 'error');
-      return;
-    }
-    sourceRoots.push(path);
-    sourceRoots.sort((a, b) => a.localeCompare(b));
-    sourceConfig[path] = true;
-    expandedNodes.add(path);
-    await loadSourceChildren(path);
-  } catch (error) {
-    toast(error.message || 'Failed to choose folder', 'error');
+  const input = document.getElementById('newSourcePath');
+  const path = (input?.value || '').trim();
+  if (!path) return;
+  if (sourceRoots.some((root) => isSamePath(root, path))) {
+    toast('This source folder is already added', 'error');
+    return;
   }
+  sourceRoots.push(path);
+  sourceRoots.sort((a, b) => a.localeCompare(b));
+  sourceConfig[path] = true;
+  expandedNodes.add(path);
+  if (input) input.value = '';
+  await loadSourceChildren(path);
 }
 
 async function reloadAllSourceTrees() {
@@ -410,9 +399,13 @@ function selectedMediaTypes() {
 }
 
 function updateAllowedFilesModeUI() {
-  const mode = document.getElementById('allowedFilesMode').value || 'media_types';
-  document.getElementById('mediaTypesGroup').style.display = mode === 'media_types' ? '' : 'none';
-  document.getElementById('extensionsGroup').style.display = mode === 'extensions' ? '' : 'none';
+  document.getElementById('mediaTypesGroup').style.display = allowedFilesMode === 'media_types' ? '' : 'none';
+  document.getElementById('extensionsGroup').style.display = allowedFilesMode === 'extensions' ? '' : 'none';
+}
+
+function toggleAllowedFilesEditor() {
+  allowedFilesMode = allowedFilesMode === 'extensions' ? 'media_types' : 'extensions';
+  updateAllowedFilesModeUI();
 }
 
 function renderMediaTypeHints() {
@@ -429,9 +422,9 @@ async function loadSettings() {
     document.getElementById('reserveGB').value      = cfg.reserve_free_gb ?? 2;
     document.getElementById('destFolder').value     = cfg.dest_folder || 'media';
     document.getElementById('fileSelectMode').value = cfg.file_select_mode || 'new';
-    document.getElementById('allowedFilesMode').value = cfg.allowed_files_mode || 'media_types';
     document.getElementById('overwriteMode').value  = cfg.overwrite_mode || 'skip';
     document.getElementById('autoCopy').checked     = !!cfg.auto_copy;
+    allowedFilesMode = cfg.allowed_files_mode || 'media_types';
     document.getElementById('mediaTypeAudio').checked = (cfg.enabled_media_types || ['audio', 'video']).includes('audio');
     document.getElementById('mediaTypeVideo').checked = (cfg.enabled_media_types || ['audio', 'video']).includes('video');
     document.getElementById('mediaTypePhoto').checked = (cfg.enabled_media_types || []).includes('photo');
@@ -456,7 +449,7 @@ async function saveSettings(event) {
     reserve_free_gb:   parseFloat(document.getElementById('reserveGB').value) || 2,
     dest_folder:       document.getElementById('destFolder').value.trim() || 'media',
     file_select_mode:  document.getElementById('fileSelectMode').value,
-    allowed_files_mode: document.getElementById('allowedFilesMode').value,
+    allowed_files_mode: allowedFilesMode,
     enabled_media_types: selectedMediaTypes(),
     allowed_extensions: parseExtensionsInput(document.getElementById('allowedExtensions').value),
     overwrite_mode:    document.getElementById('overwriteMode').value,