infra: migrate application from Mac mini to GPU server

- Integrate ollama + ai-gateway into root docker-compose.yml
  (NVIDIA GPU runtime, single compose for all services)
- Change NAS mount from SMB (NAS_SMB_PATH) to NFS (NAS_NFS_PATH)
  Default: /mnt/nas/Document_Server (fstab registered on GPU server)
- Update config.yaml AI endpoints:
  primary → Mac mini MLX via Tailscale (100.76.254.116:8800)
  fallback/embedding/vision/rerank → ollama (same Docker network)
  gateway → ai-gateway (same Docker network)
- Update credentials.env.example (remove GPU_SERVER_IP, add NFS path)
- Mark gpu-server/docker-compose.yml as deprecated
- Update CLAUDE.md network diagram and AI model config
- Update architecture.md, deploy.md, devlog.md for GPU server as main
- Caddyfile: auto_https off, HTTP only (TLS at upstream proxy)
- Caddy port: 127.0.0.1:8080:80 (localhost only)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

config.yaml

@@ -2,17 +2,17 @@
 
 ai:
   gateway:
-    endpoint: "http://gpu-server:8080"
+    endpoint: "http://ai-gateway:8080"
 
   models:
     primary:
-      endpoint: "http://host.docker.internal:8800/v1/chat/completions"
+      endpoint: "http://100.76.254.116:8800/v1/chat/completions"
       model: "mlx-community/Qwen3.5-35B-A3B-4bit"
       max_tokens: 4096
       timeout: 60
 
     fallback:
-      endpoint: "http://gpu-server:11434/v1/chat/completions"
+      endpoint: "http://ollama:11434/v1/chat/completions"
       model: "qwen3.5:35b-a3b"
       max_tokens: 4096
       timeout: 120
@@ -25,15 +25,15 @@ ai:
       require_explicit_trigger: true
 
     embedding:
-      endpoint: "http://gpu-server:11434/api/embeddings"
+      endpoint: "http://ollama:11434/api/embeddings"
       model: "nomic-embed-text"
 
     vision:
-      endpoint: "http://gpu-server:11434/api/generate"
+      endpoint: "http://ollama:11434/api/generate"
       model: "Qwen2.5-VL-7B"
 
     rerank:
-      endpoint: "http://gpu-server:11434/api/rerank"
+      endpoint: "http://ollama:11434/api/rerank"
       model: "bge-reranker-v2-m3"
 
 nas: