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>

scripts/generate_encryption_key.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+"""
+Generate a Fernet encryption key for token encryption.
+
+Usage:
+    python scripts/generate_encryption_key.py
+
+Add the output to your .env file as ENCRYPTION_KEY.
+"""
+from cryptography.fernet import Fernet
+
+if __name__ == "__main__":
+    key = Fernet.generate_key().decode()
+    print("=" * 70)
+    print("Generated Encryption Key:")
+    print("=" * 70)
+    print(key)
+    print("=" * 70)
+    print("\nAdd this to your .env file:")
+    print(f"ENCRYPTION_KEY={key}")
+    print("\n⚠️  Keep this key secure and never commit it to git!")