perf(obsidian): optimize folder tree for large vaults

The previous implementation read ALL file contents to get frontmatter
when browsing notes, which caused massive slowdown for large vaults
(13k+ files = 13k+ HTTP requests).

Changes:
- Add listAllNotePaths() function that only gets file paths (fast)
- Build folder tree from paths only, no content reading
- Lazy load file content only when user clicks on a file
- Change message from "Loading all notes" to "Loading file list"
- Add logging to show file count being displayed

Performance improvement:
- Before: O(n) HTTP requests where n = number of files
- After: O(1) - just the recursive directory scan
- File content loaded on-demand (1 request per clicked file)

This makes the folder tree instant even for vaults with 10k+ files.

modules/io/obsidian-bridge.js

@@ -463,7 +463,7 @@ Add your lore here...
     return results;
   }
 
-  // List all notes with basic info
+  // List all notes with basic info (reads frontmatter - slow for large vaults)
   async function listAllNotes() {
     const allFiles = await getVaultFiles();
     const notes = [];
@@ -495,6 +495,25 @@ Add your lore here...
     return notes;
   }
 
+  // List just file paths (fast - no content reading)
+  async function listAllNotePaths() {
+    const allFiles = await getVaultFiles();
+
+    INFO && console.log(`listAllNotePaths: Found ${allFiles.length} files`);
+
+    // Convert to note objects with just path and name
+    const notes = allFiles.map(filePath => ({
+      path: filePath,
+      name: filePath.split("/").pop().replace(".md", ""),
+      folder: filePath.includes("/") ? filePath.substring(0, filePath.lastIndexOf("/")) : ""
+    }));
+
+    // Sort by path
+    notes.sort((a, b) => a.path.localeCompare(b.path));
+
+    return notes;
+  }
+
   return {
     init,
     config,
@@ -509,7 +528,8 @@ Add your lore here...
     findNoteByFmgId,
     generateNoteTemplate,
     searchNotes,
-    listAllNotes
+    listAllNotes,
+    listAllNotePaths
   };
 })();