feat: Add credentials management system and comprehensive testing

- Add credentials management system with automatic saving and updates
- Add upload form URL to JSON output
- Add Ollama model information to JSON output
- Implement credential update system (update_credentials.sh)
- Implement credential save system (save_credentials.sh)
- Add comprehensive test suites (infrastructure, n8n, PostgREST, complete system)
- Add workflow auto-reload system with systemd service
- Add detailed documentation (CREDENTIALS_MANAGEMENT.md, TEST_REPORT.md, VERIFICATION_SUMMARY.md)
- Improve n8n setup with robust API-based workflow import
- Add .gitignore for credentials directory
- All tests passing (40+ test cases)

Key Features:
- Credentials automatically saved to credentials/<hostname>.json
- Update Ollama URL from IP to hostname without container restart
- Comprehensive testing with 4 test suites
- Full documentation and examples
- Production-ready system

credentials/.gitignore

@@ -0,0 +1,5 @@
+# Ignore all credential files
+*.json
+
+# Except the example file
+!example-credentials.json

credentials/example-credentials.json

@@ -0,0 +1,52 @@
+{
+  "container": {
+    "ctid": 769276659,
+    "hostname": "sb-1769276659",
+    "fqdn": "sb-1769276659.userman.de",
+    "ip": "192.168.45.45",
+    "vlan": 90
+  },
+  "urls": {
+    "n8n_internal": "http://192.168.45.45:5678/",
+    "n8n_external": "https://sb-1769276659.userman.de",
+    "postgrest": "http://192.168.45.45:3000",
+    "chat_webhook": "https://sb-1769276659.userman.de/webhook/rag-chat-webhook/chat",
+    "chat_internal": "http://192.168.45.45:5678/webhook/rag-chat-webhook/chat",
+    "upload_form": "https://sb-1769276659.userman.de/form/rag-upload-form",
+    "upload_form_internal": "http://192.168.45.45:5678/form/rag-upload-form"
+  },
+  "postgres": {
+    "host": "postgres",
+    "port": 5432,
+    "db": "customer",
+    "user": "customer",
+    "password": "EXAMPLE_PASSWORD"
+  },
+  "supabase": {
+    "url": "http://postgrest:3000",
+    "url_external": "http://192.168.45.45:3000",
+    "anon_key": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
+    "service_role_key": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
+    "jwt_secret": "EXAMPLE_JWT_SECRET"
+  },
+  "ollama": {
+    "url": "http://192.168.45.3:11434",
+    "model": "ministral-3:3b",
+    "embedding_model": "nomic-embed-text:latest"
+  },
+  "n8n": {
+    "encryption_key": "EXAMPLE_ENCRYPTION_KEY",
+    "owner_email": "admin@userman.de",
+    "owner_password": "EXAMPLE_PASSWORD",
+    "secure_cookie": false
+  },
+  "log_file": "/root/customer-installer/logs/sb-1769276659.log",
+  "created_at": "2026-01-24T18:00:00+01:00",
+  "updateable_fields": {
+    "ollama_url": "Can be updated to use hostname instead of IP (e.g., http://ollama.local:11434)",
+    "ollama_model": "Can be changed to different model (e.g., llama3.2:3b)",
+    "embedding_model": "Can be changed to different embedding model",
+    "postgres_password": "Can be updated (requires container restart)",
+    "n8n_owner_password": "Can be updated (requires container restart)"
+  }
+}