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/utils/silent-debug.ts

@@ -3,26 +3,31 @@
  *
  * Semantic meaning: "When the happy path fails, this is an error, but we have a fallback."
  *
- * NOTE: This utility is to be used like Frank's Red Hot, we put that shit on everything.
- *
- * USE THIS INSTEAD OF SILENT FAILURES!
- * Stop doing this: `const value = something || '';`
- * Start doing this: `const value = something || happy_path_error__with_fallback('something was undefined');`
- *
  * Logs to ~/.claude-mem/silent.log and returns a fallback value.
  * Check logs with `npm run logs:silent`
  *
- * Usage:
- *   import { happy_path_error__with_fallback } from '../utils/silent-debug.js';
+ * Use happy_path_error__with_fallback for:
+ * ✅ Unexpected null/undefined values that should theoretically never happen
+ * ✅ Defensive coding where silent fallback is acceptable
+ * ✅ Situations where you want to track unexpected nulls without breaking execution
  *
- *   const title = obs.title || happy_path_error__with_fallback('obs.title missing', { obs });
- *   const name = user.name || happy_path_error__with_fallback('user.name missing', { user }, 'Anonymous');
+ * DO NOT use for:
+ * ❌ Nullable fields with valid default behavior (use direct || defaults)
+ * ❌ Critical validation failures (use logger.warn or throw Error)
+ * ❌ Try-catch blocks where error is already logged (redundant)
  *
- *   try {
- *     doSomething();
- *   } catch (error) {
- *     happy_path_error__with_fallback('doSomething failed', { error });
- *   }
+ * Good examples:
+ *   // Truly unexpected null (should never happen in theory)
+ *   const id = session.id || happy_path_error__with_fallback('session.id missing', { session });
+ *
+ * Bad examples (use direct defaults instead):
+ *   // Nullable field with valid empty default
+ *   const title = obs.title || happy_path_error__with_fallback('obs.title missing', { obs }, '(untitled)');
+ *   // BETTER: const title = obs.title || '(untitled)';
+ *
+ *   // Array that can validly be undefined/null
+ *   const count = obs.files?.length ?? (happy_path_error__with_fallback('obs.files missing', { obs }), 0);
+ *   // BETTER: const count = obs.files?.length ?? 0;
  */
 
 import { appendFileSync } from 'fs';