Standardize and enhance error handling across hooks and worker service (#295)

* Enhance error logging in hooks

- Added detailed error logging in context-hook, new-hook, save-hook, and summary-hook to capture status, project, port, and relevant session information on failures.
- Improved error messages thrown in save-hook and summary-hook to include specific context about the failure.

* Refactor migration logging to use console.log instead of console.error

- Updated SessionSearch and SessionStore classes to replace console.error with console.log for migration-related messages.
- Added notes in the documentation to clarify the use of console.log for migration messages due to the unavailability of the structured logger during constructor execution.

* Refactor SDKAgent and silent-debug utility to simplify error handling

- Updated SDKAgent to use direct defaults instead of happy_path_error__with_fallback for non-critical fields such as last_user_message, last_assistant_message, title, filesRead, filesModified, concepts, and summary.request.
- Enhanced silent-debug documentation to clarify appropriate use cases for happy_path_error__with_fallback, emphasizing its role in handling unexpected null/undefined values while discouraging its use for nullable fields with valid defaults.

* fix: correct happy_path_error__with_fallback usage to prevent false errors

Fixes false "Missing cwd" and "Missing transcript_path" errors that were
flooding silent.log even when values were present.

Root cause: happy_path_error__with_fallback was being called unconditionally
instead of only when the value was actually missing.

Pattern changed from:
  value: happy_path_error__with_fallback('Missing', {}, value || '')

To correct usage:
  value: value || happy_path_error__with_fallback('Missing', {}, '')

Fixed in:
- src/hooks/save-hook.ts (PostToolUse hook)
- src/hooks/summary-hook.ts (Stop hook)
- src/services/worker/http/routes/SessionRoutes.ts (2 instances)

Impact: Eliminates false error noise, making actual errors visible.

Addresses issue #260 - users were seeing "Missing cwd" errors despite
Claude Code correctly passing all required fields.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

* Enhance error logging and handling across services

- Improved error messages in SessionStore to include project context when fetching boundary observations and timestamps.
- Updated ChromaSync error handling to provide more informative messages regarding client initialization failures, including the project context.
- Enhanced error logging in WorkerService to include the package path when reading version fails.
- Added detailed error logging in worker-utils to capture expected and running versions during health checks.
- Extended WorkerErrorMessageOptions to include actualError for more informative restart instructions.

* Refactor error handling in hooks to use standardized fetch error handler

- Introduced a new error handler `handleFetchError` in `shared/error-handler.ts` to standardize logging and user-facing error messages for fetch failures across hooks.
- Updated `context-hook.ts`, `new-hook.ts`, `save-hook.ts`, and `summary-hook.ts` to utilize the new error handler, improving consistency and maintainability.
- Removed redundant imports and error handling logic related to worker restart instructions from the hooks.

* feat: add comprehensive error handling tests for hooks and ChromaSync client

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

src/services/sqlite/SessionSearch.ts

@@ -44,6 +44,9 @@ export class SessionSearch {
    * - Tables maintained but search paths removed
    * - Triggers still fire to keep tables synchronized
    *
+   * Note: Using console.log for migration messages since they run during constructor
+   * before structured logger is available. Actual errors use console.error.
+   *
    * TODO: Remove FTS5 infrastructure in future major version (v7.0.0)
    */
   private ensureFTSTables(): void {
@@ -57,7 +60,7 @@ export class SessionSearch {
         return;
       }
 
-      console.error('[SessionSearch] Creating FTS5 tables...');
+      console.log('[SessionSearch] Creating FTS5 tables...');
 
       // Create observations_fts virtual table
       this.db.run(`
@@ -141,7 +144,7 @@ export class SessionSearch {
         END;
       `);
 
-      console.error('[SessionSearch] FTS5 tables created successfully');
+      console.log('[SessionSearch] FTS5 tables created successfully');
     } catch (error: any) {
       console.error('[SessionSearch] FTS migration error:', error.message);
     }