Refactor logging in hooks, services, and routes to use centralized logger

- Replaced console.log and console.error statements with logger.info and logger.error in new-hook.ts, SDKAgent.ts, SessionManager.ts, and SessionRoutes.ts for consistent logging.
- Introduced log file creation and management in logger.ts, ensuring logs are saved to a file with a date-based naming convention.
- Enhanced error handling in logger to prevent crashes if log file operations fail.

src/utils/logger.ts

@@ -4,6 +4,8 @@
  */
 
 import { SettingsDefaultsManager } from '../shared/SettingsDefaultsManager.js';
+import { appendFileSync, existsSync, mkdirSync } from 'fs';
+import { join } from 'path';
 
 export enum LogLevel {
   DEBUG = 0,
@@ -25,19 +27,55 @@ interface LogContext {
 class Logger {
   private level: LogLevel | null = null;
   private useColor: boolean;
+  private logFilePath: string | null = null;
 
   constructor() {
     // Disable colors when output is not a TTY (e.g., PM2 logs)
     this.useColor = process.stdout.isTTY ?? false;
+    this.initializeLogFile();
   }
 
   /**
-   * Lazy-load log level from settings (breaks circular dependency with SettingsDefaultsManager)
+   * Initialize log file path and ensure directory exists
+   */
+  private initializeLogFile(): void {
+    try {
+      // Get data directory from settings
+      const dataDir = SettingsDefaultsManager.get('CLAUDE_MEM_DATA_DIR');
+      const logsDir = join(dataDir, 'logs');
+
+      // Ensure logs directory exists
+      if (!existsSync(logsDir)) {
+        mkdirSync(logsDir, { recursive: true });
+      }
+
+      // Create log file path with date
+      const date = new Date().toISOString().split('T')[0];
+      this.logFilePath = join(logsDir, `claude-mem-${date}.log`);
+    } catch (error) {
+      // If log file initialization fails, just log to console
+      console.error('[LOGGER] Failed to initialize log file:', error);
+      this.logFilePath = null;
+    }
+  }
+
+  /**
+   * Lazy-load log level from settings file (not hardcoded defaults!)
    */
   private getLevel(): LogLevel {
     if (this.level === null) {
-      const envLevel = SettingsDefaultsManager.get('CLAUDE_MEM_LOG_LEVEL').toUpperCase();
-      this.level = LogLevel[envLevel as keyof typeof LogLevel] ?? LogLevel.INFO;
+      try {
+        // Load settings from file to get user's actual log level
+        const dataDir = SettingsDefaultsManager.get('CLAUDE_MEM_DATA_DIR');
+        const settingsPath = join(dataDir, 'settings.json');
+        const settings = SettingsDefaultsManager.loadFromFile(settingsPath);
+        const envLevel = settings.CLAUDE_MEM_LOG_LEVEL.toUpperCase();
+        this.level = LogLevel[envLevel as keyof typeof LogLevel] ?? LogLevel.INFO;
+      } catch (error) {
+        // Fallback to INFO if settings can't be loaded
+        console.error('[LOGGER] Failed to load settings, using INFO level:', error);
+        this.level = LogLevel.INFO;
+      }
     }
     return this.level;
   }
@@ -219,12 +257,22 @@ class Logger {
 
     const logLine = `[${timestamp}] [${levelStr}] [${componentStr}] ${correlationStr}${message}${contextStr}${dataStr}`;
 
-    // Output to appropriate stream
+    // Output to console
     if (level === LogLevel.ERROR) {
       console.error(logLine);
     } else {
       console.log(logLine);
     }
+
+    // Output to log file
+    if (this.logFilePath) {
+      try {
+        appendFileSync(this.logFilePath, logLine + '\n', 'utf8');
+      } catch (error) {
+        // If file write fails, just continue (don't crash)
+        console.error('[LOGGER] Failed to write to log file:', error);
+      }
+    }
   }
 
   // Public logging methods