docs: update all READMEs for v1.1.0

Add Electron desktop app section, document all 8 plugins, update
features list (assets, super-buckets, find/replace, arrow nav, PDF
upload), fix relay docs (chat shipped, not future), add missing API
endpoints, correct electron data storage paths and php-bin fetch info.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

electron/README.md

@@ -10,8 +10,13 @@ per platform so users don't need PHP installed.
 3. A `BrowserWindow` loads `http://127.0.0.1:<port>/`
 4. On quit, the PHP process is killed cleanly
 
-Data is stored in `data/hyprcrd.db` (SQLite), relative to the project root
-(dev) or inside the app's `resources/` directory (packaged).
+User data (database + uploads) is stored **outside** the app bundle so it
+survives updates:
+
+- **Dev**: `electron/appdata/`
+- **Linux**: `~/.config/hyprcrd/data/`
+- **macOS**: `~/Library/Application Support/hyprcrd/data/`
+- **Windows**: `%APPDATA%/hyprcrd/data/`
 
 ## Development