Refactor hooks and worker service for improved error handling and initialization

- Removed try-catch blocks in new-hook, save-hook, and summary-hook for cleaner flow.
- Enhanced error handling in save and summary hooks to throw errors instead of logging and returning.
- Introduced ensureWorkerRunning utility to manage worker service lifecycle and health checks.
- Replaced dynamic port allocation with a fixed port for the worker service.
- Simplified path management and removed unused port allocator utility.
- Added database schema initialization for fresh installations and improved migration handling.

.gitignore

@@ -6,4 +6,5 @@ node_modules/
 *.tmp
 *.temp
 .claude/
-plugin/data/
+plugin/data/
+plugin/data.backup/