feat(obsidian): add collapsible folder tree for browsing notes

Replaced flat list with hierarchical folder tree structure for better
navigation when browsing vault notes.

**Features:**
- Collapsible folders with ▼/▶ toggle arrows
- Proper indentation showing folder hierarchy
- 📁 folder and 📄 file icons
- Click folder name to expand/collapse
- Click file to select it
- Handles root-level files and nested folders
- Hover highlights for files

**Functions added:**
- buildFolderTree(): Converts flat note list to tree structure
- renderFolderTree(): Recursively renders folders with nesting
- renderFiles(): Renders files at current folder level

Perfect for vaults organized like:
```
State1/
  Province1/
    City1.md
    City2.md
  Province2/
    City3.md
State2/
  Province3/
    City4.md
```

Much easier to navigate than a flat list of 100+ notes!

index.html

@@ -8282,7 +8282,7 @@
     <script defer src="modules/io/cloud.js?v=1.106.0"></script>
     <script defer src="modules/io/export.js?v=1.108.11"></script>
     <script defer src="modules/io/obsidian-bridge.js?v=1.108.13.3"></script>
-    <script defer src="modules/ui/obsidian-notes-editor.js?v=1.108.13.3"></script>
+    <script defer src="modules/ui/obsidian-notes-editor.js?v=1.108.13.4"></script>
     <script defer src="modules/ui/obsidian-config.js?v=1.108.13"></script>
 
     <script defer src="modules/renderers/draw-features.js?v=1.108.2"></script>

modules/ui/obsidian-notes-editor.js

@@ -310,27 +310,14 @@ async function promptCreateNewNote(elementId, elementType, coordinates) {
           return;
         }
 
-        resultsDiv.innerHTML = allNotes
-          .map(
-            (note, index) => `
-          <div class="browse-result" data-index="${index}" style="
-            padding: 8px;
-            margin: 4px 0;
-            border: 1px solid #ddd;
-            border-radius: 4px;
-            cursor: pointer;
-            background: white;
-          " onmouseover="this.style.background='#e8e8e8'" onmouseout="this.style.background='white'">
-            <div style="font-weight: bold;">${note.name}</div>
-            <div style="font-size: 0.85em; color: #666;">${note.path}</div>
-          </div>
-        `
-          )
-          .join("");
+        // Build folder tree
+        const tree = buildFolderTree(allNotes);
+        resultsDiv.innerHTML = renderFolderTree(tree, allNotes);
 
-        // Add click handlers
-        document.querySelectorAll(".browse-result").forEach((el, index) => {
+        // Add click handlers to files
+        document.querySelectorAll(".tree-file").forEach(el => {
           el.addEventListener("click", async () => {
+            const index = parseInt(el.dataset.index);
             $("#alert").dialog("close");
             try {
               const note = allNotes[index];
@@ -346,6 +333,17 @@ async function promptCreateNewNote(elementId, elementType, coordinates) {
             }
           });
         });
+
+        // Add click handlers to folder toggles
+        document.querySelectorAll(".tree-folder-toggle").forEach(el => {
+          el.addEventListener("click", e => {
+            e.stopPropagation();
+            const folder = el.parentElement.nextElementSibling;
+            const isCollapsed = folder.style.display === "none";
+            folder.style.display = isCollapsed ? "block" : "none";
+            el.textContent = isCollapsed ? "▼" : "▶";
+          });
+        });
       } catch (error) {
         resultsDiv.innerHTML = `<p style='color: red;'>Failed to load notes: ${error.message}</p>`;
       }
@@ -359,6 +357,77 @@ async function promptCreateNewNote(elementId, elementType, coordinates) {
   });
 }
 
+function buildFolderTree(notes) {
+  const root = {folders: {}, files: []};
+
+  notes.forEach((note, index) => {
+    const parts = note.path.split("/");
+    const fileName = parts[parts.length - 1];
+
+    if (parts.length === 1) {
+      // Root level file
+      root.files.push({name: fileName, index, path: note.path});
+    } else {
+      // Navigate/create folder structure
+      let current = root;
+      for (let i = 0; i < parts.length - 1; i++) {
+        const folderName = parts[i];
+        if (!current.folders[folderName]) {
+          current.folders[folderName] = {folders: {}, files: []};
+        }
+        current = current.folders[folderName];
+      }
+      // Add file to final folder
+      current.files.push({name: fileName, index, path: note.path});
+    }
+  });
+
+  return root;
+}
+
+function renderFolderTree(node, allNotes, indent = 0) {
+  let html = "";
+  const indentPx = indent * 20;
+
+  // Render folders
+  for (const [folderName, folderData] of Object.entries(node.folders || {})) {
+    html += `
+      <div style="margin-left: ${indentPx}px;">
+        <div style="padding: 4px; cursor: pointer; user-select: none;">
+          <span class="tree-folder-toggle" style="display: inline-block; width: 16px; font-size: 12px;">▼</span>
+          <span style="font-weight: bold;">📁 ${folderName}</span>
+        </div>
+        <div class="tree-folder-content" style="display: block;">
+          ${renderFolderTree(folderData, allNotes, indent + 1)}
+        </div>
+      </div>
+    `;
+  }
+
+  // Render files in current folder
+  html += renderFiles(node.files || [], indent);
+
+  return html;
+}
+
+function renderFiles(files, indent) {
+  const indentPx = indent * 20;
+  return files
+    .map(
+      file => `
+    <div class="tree-file" data-index="${file.index}" style="
+      margin-left: ${indentPx}px;
+      padding: 4px 8px;
+      cursor: pointer;
+      border-radius: 3px;
+    " onmouseover="this.style.background='#e8e8e8'" onmouseout="this.style.background='transparent'">
+      <span style="font-size: 12px;">📄</span> ${file.name.replace(".md", "")}
+    </div>
+  `
+    )
+    .join("");
+}
+
 function getElementData(elementId, elementType) {
   // Extract element data based on type
   if (elementType === "burg") {