fix(cloudflare): add backend network to compose templates and improve tunnel diagnostics

- Add 'backend' external network to all compose templates so cloudflared can reach tool containers
- Add better error handling and logging to create_tunnel() with specific error messages for auth failures
- Add check_cloudflare_config() diagnostic function
- Add /health/cloudflare endpoint to verify Cloudflare configuration
- Import Any type for type hints

apps/api/src/main.py

@@ -122,7 +122,13 @@ services:
       - {{REPO_PATH}}:/config/workspace
     ports:
       - "8443:8443"
-    restart: unless-stopped""",
+    networks:
+      - backend
+    restart: unless-stopped
+
+networks:
+  backend:
+    external: true""",
                 "default_port": 8443,
                 "required_variables": ["REPO_PATH", "TOOL_NAME"],
             },
@@ -144,7 +150,13 @@ services:
       - {{REPO_PATH}}:/home/jovyan/work
     ports:
       - "8888:8888"
-    restart: unless-stopped""",
+    networks:
+      - backend
+    restart: unless-stopped
+
+networks:
+  backend:
+    external: true""",
                 "required_variables": ["REPO_PATH", "TOOL_NAME"],
             },
             {
@@ -170,10 +182,16 @@ services:
              tail -f /dev/null"
     stdin_open: true
     tty: true
+    networks:
+      - backend
     restart: unless-stopped
 
 volumes:
-  opencode_home:""",
+  opencode_home:
+
+networks:
+  backend:
+    external: true""",
                 "required_variables": ["REPO_PATH", "TOOL_NAME"],
             },
         ]