feat: session rename — double-click or pencil icon to set custom session names

- Double-click session name in sidebar to rename inline
- Pencil icon on hover for discoverability
- Custom names persisted in localStorage
- Enter to confirm, Escape to cancel, blur to save
- Clear name to revert to auto-generated display name
- Search filter respects custom names
- i18n for all 8 languages

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pinchchat",
-  "version": "1.61.0",
+  "version": "1.62.0",
   "description": "A sleek, dark-themed webchat UI for OpenClaw — monitor sessions, stream responses, and inspect tool calls in real-time.",
   "type": "module",
   "repository": {