feat(tkds): 독립 대시보드 서비스 분리 (tkds.technicalkorea.net)

대시보드를 gateway(tkfb)에서 분리하여 독립 서비스 tkds로 이동.
- tkds/web: nginx + dashboard.html 신규 서비스 (port 30780)
- gateway: /login 복원, /dashboard → tkds 301 리다이렉트
- 전체 시스템 getLoginUrl() → tkds.technicalkorea.net/dashboard로 변경

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -416,6 +416,21 @@ services:
   # AI Service — 맥미니로 이전됨 (~/docker/tk-ai-service/)
   # =================================================================
 
+  # =================================================================
+  # Dashboard (tkds)
+  # =================================================================
+
+  tkds-web:
+    build:
+      context: ./tkds/web
+      dockerfile: Dockerfile
+    container_name: tk-tkds-web
+    restart: unless-stopped
+    ports:
+      - "30780:80"
+    networks:
+      - tk-network
+
   # =================================================================
   # Gateway
   # =================================================================
@@ -470,6 +485,7 @@ services:
       - TUNNEL_TOKEN=${CLOUDFLARE_TUNNEL_TOKEN}
     depends_on:
       - gateway
+      - tkds-web
       - system2-web
       - system3-web
       - tkpurchase-web