Major updates: LinkedIn auto-posting, timezone fixes, and Docker improvements

Features:
- Add LinkedIn OAuth integration and auto-posting functionality
- Add scheduler service for automated post publishing
- Add metadata field to generated_posts for LinkedIn URLs
- Add privacy policy page for LinkedIn API compliance
- Add company management features and employee accounts
- Add license key system for company registrations

Fixes:
- Fix timezone issues (use UTC consistently across app)
- Fix datetime serialization errors in database operations
- Fix scheduling timezone conversion (local time to UTC)
- Fix import errors (get_database -> db)

Infrastructure:
- Update Docker setup to use port 8001 (avoid conflicts)
- Add SSL support with nginx-proxy and Let's Encrypt
- Add LinkedIn setup documentation
- Add migration scripts for schema updates

Services:
- Add linkedin_service.py for LinkedIn API integration
- Add scheduler_service.py for background job processing
- Add storage_service.py for Supabase Storage
- Add email_service.py improvements
- Add encryption utilities for token storage

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

src/agents/researcher.py

@@ -1,7 +1,7 @@
 """Research agent using Perplexity."""
 import json
 import random
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from typing import Dict, Any, List
 from loguru import logger
 
@@ -258,7 +258,7 @@ Gib deine Antwort im folgenden JSON-Format zurück:
         pain_points_text = ", ".join(pain_points) if pain_points else "Allgemeine Business-Probleme"
 
         # Current date for time-specific searches
-        today = datetime.now()
+        today = datetime.now(timezone.utc)
         date_str = today.strftime("%d. %B %Y")
         week_ago = (today - timedelta(days=7)).strftime("%d. %B %Y")