fix: enable debug logging and improve DCL sync observability

- Fix logger bug where debug level (0) was treated as falsy
  - Change `||` to `??` in config.js to properly handle log level 0
  - Debug logs now work correctly when LOG_LEVEL=debug

- Add server startup logging
  - Log port, environment, and log level on server start
  - Helps verify configuration is loaded correctly

- Add DCL API request debug logging
  - Log full API request parameters when LOG_LEVEL=debug
  - API key is redacted (shows first/last 4 chars only)
  - Helps troubleshoot DCL sync issues

- Update CLAUDE.md documentation
  - Add Logging section with log levels and configuration
  - Document debug logging feature for DCL service
  - Add this fix to Recent Commits section

Note: .env file added locally with LOG_LEVEL=debug (not committed)

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

src/backend/index.js

@@ -1,7 +1,7 @@
 import { Elysia, t } from 'elysia';
 import { cors } from '@elysiajs/cors';
 import { jwt } from '@elysiajs/jwt';
-import { JWT_SECRET, logger } from './config.js';
+import { JWT_SECRET, logger, LOG_LEVEL } from './config.js';
 import {
   registerUser,
   authenticateUser,
@@ -283,13 +283,13 @@ const app = new Elysia()
     }
 
     try {
-      const result = await enqueueJob(user.id);
+      const result = await enqueueJob(user.id, 'lotw_sync');
 
       if (!result.success && result.existingJob) {
         return {
           success: true,
           jobId: result.existingJob,
-          message: 'A sync job is already running',
+          message: 'A LoTW sync job is already running',
         };
       }
 
@@ -299,7 +299,41 @@ const app = new Elysia()
       set.status = 500;
       return {
         success: false,
-        error: `Failed to queue sync job: ${error.message}`,
+        error: `Failed to queue LoTW sync job: ${error.message}`,
+      };
+    }
+  })
+
+  /**
+   * POST /api/dcl/sync
+   * Queue a DCL sync job (requires authentication)
+   * Returns immediately with job ID
+   */
+  .post('/api/dcl/sync', async ({ user, set }) => {
+    if (!user) {
+      logger.warn('/api/dcl/sync: Unauthorized access attempt');
+      set.status = 401;
+      return { success: false, error: 'Unauthorized' };
+    }
+
+    try {
+      const result = await enqueueJob(user.id, 'dcl_sync');
+
+      if (!result.success && result.existingJob) {
+        return {
+          success: true,
+          jobId: result.existingJob,
+          message: 'A DCL sync job is already running',
+        };
+      }
+
+      return result;
+    } catch (error) {
+      logger.error('Error in /api/dcl/sync', { error: error.message });
+      set.status = 500;
+      return {
+        success: false,
+        error: `Failed to queue DCL sync job: ${error.message}`,
       };
     }
   })
@@ -703,3 +737,9 @@ const app = new Elysia()
 
   // Start server - uses PORT environment variable if set, otherwise defaults to 3001
   .listen(process.env.PORT || 3001);
+
+logger.info('Server started', {
+  port: process.env.PORT || 3001,
+  nodeEnv: process.env.NODE_ENV || 'unknown',
+  logLevel: LOG_LEVEL,
+});