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>

credentials.env.example

@@ -10,22 +10,18 @@ POSTGRES_DB=pkm
 POSTGRES_USER=pkm
 POSTGRES_PASSWORD=
 
-# ─── AI: Mac mini MLX (Qwen3.5, 기본 모델) ───
-MLX_ENDPOINT=http://localhost:8800/v1/chat/completions
+# ─── AI: Mac mini MLX (Tailscale 경유, Qwen3.5 기본 모델) ───
+MLX_ENDPOINT=http://100.76.254.116:8800/v1/chat/completions
 MLX_MODEL=mlx-community/Qwen3.5-35B-A3B-4bit
 
-# ─── AI: GPU 서버 ───
-GPU_SERVER_IP=
-GPU_EMBED_PORT=11434
-
 # ─── AI: Claude API (종량제, 복잡한 분석 전용) ───
 CLAUDE_API_KEY=
 
-# ─── AI Gateway (GPU 서버) ───
-AI_GATEWAY_ENDPOINT=http://gpu-server:8080
+# ─── AI Gateway (같은 Docker 네트워크) ───
+AI_GATEWAY_ENDPOINT=http://ai-gateway:8080
 
-# ─── Synology NAS ───
-NAS_SMB_PATH=/Volumes/Document_Server
+# ─── NAS (NFS 마운트) ───
+NAS_NFS_PATH=/mnt/nas/Document_Server
 NAS_DOMAIN=ds1525.hyungi.net
 NAS_TAILSCALE_IP=100.101.79.37
 NAS_PORT=15001
@@ -51,7 +47,3 @@ TOTP_SECRET=
 
 # ─── 국가법령정보센터 (법령 모니터링) ───
 LAW_OC=
-
-# ─── TKSafety API (나중에 활성화) ───
-#TKSAFETY_HOST=tksafety.technicalkorea.net
-#TKSAFETY_PORT=