refactor: replace happy_path_error__with_fallback with logger.happyPathError (#313)

- Removed all instances of happy_path_error__with_fallback from various hooks, services, and utilities.
- Introduced logger.happyPathError for consistent logging of unexpected nulls and fallback values.
- Updated the logger utility to include a new happyPathError method with enhanced context and stack trace.
- Deprecated silent-debug utility as all logging functionality has been migrated to the logger.

src/services/worker/SDKAgent.ts

@@ -14,7 +14,6 @@ import path from 'path';
 import { DatabaseManager } from './DatabaseManager.js';
 import { SessionManager } from './SessionManager.js';
 import { logger } from '../../utils/logger.js';
-import { happy_path_error__with_fallback } from '../../utils/silent-debug.js';
 import { parseObservations, parseSummary } from '../../sdk/parser.js';
 import { buildInitPrompt, buildObservationPrompt, buildSummaryPrompt, buildContinuationPrompt } from '../../sdk/prompts.js';
 import { SettingsDefaultsManager } from '../../shared/SettingsDefaultsManager.js';