feat: implement unsaved changes handling in editor and sidebar

- Introduced global state management for unsaved changes and pending navigation using Jotai atoms.
- Updated the editor component to sync local unsaved changes with global state and handle navigation prompts.
- Enhanced sidebar functionality to check for unsaved changes before navigating to a new note.
- Added cleanup logic for global state on component unmount to prevent stale data.

surfsense_web/contracts/types/chat.types.ts

@@ -14,7 +14,7 @@ export const chatSummary = z.object({
 });
 
 export const chatDetails = chatSummary.extend({
-	initial_connectors: z.array(z.string()),
+	initial_connectors: z.array(z.string()).nullable().optional(),
 	messages: z.array(z.any()),
 });