chore: update n8n to v1.114.3 and optimize template fetching

Updates:
- Updated n8n from 1.113.3 to 1.114.3
- Updated n8n-core from 1.112.1 to 1.113.1
- Updated n8n-workflow from 1.110.0 to 1.111.0
- Updated @n8n/n8n-nodes-langchain from 1.112.2 to 1.113.1
- Rebuilt node database with 536 nodes
- Updated template database (2647 → 2653, +6 new templates)
- Sanitized 24 templates to remove API tokens

Performance Improvements:
- Optimized template update to fetch only last 2 weeks
- Reduced update time from 10+ minutes to ~60 seconds
- Added getMostRecentTemplateDate() to TemplateRepository
- Modified TemplateFetcher to support date-based filtering
- Update mode now fetches templates since (most_recent - 14 days)

All tests passing (933 unit, 249 integration)

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

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

package.json

@@ -132,15 +132,15 @@
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.13.2",
-    "@n8n/n8n-nodes-langchain": "^1.112.2",
+    "@n8n/n8n-nodes-langchain": "^1.113.1",
     "@supabase/supabase-js": "^2.57.4",
     "dotenv": "^16.5.0",
     "express": "^5.1.0",
     "express-rate-limit": "^7.1.5",
     "lru-cache": "^11.2.1",
-    "n8n": "^1.113.3",
-    "n8n-core": "^1.112.1",
-    "n8n-workflow": "^1.110.0",
+    "n8n": "^1.114.3",
+    "n8n-core": "^1.113.1",
+    "n8n-workflow": "^1.111.0",
     "openai": "^4.77.0",
     "sql.js": "^1.13.0",
     "uuid": "^10.0.0",