docs(proxy): clarify proxy_url usage in documentation

src/grist_mcp/main.py

@@ -252,11 +252,18 @@ def create_app(config: Config):
 
 def _print_mcp_config(external_port: int, tokens: list) -> None:
     """Print Claude Code MCP configuration."""
+    # Use GRIST_MCP_URL if set, otherwise fall back to localhost
+    base_url = os.environ.get("GRIST_MCP_URL")
+    if base_url:
+        sse_url = f"{base_url.rstrip('/')}/sse"
+    else:
+        sse_url = f"http://localhost:{external_port}/sse"
+
     print()
     print("Claude Code MCP configuration (copy-paste to add):")
     for t in tokens:
         config = (
-            f'{{"type": "sse", "url": "http://localhost:{external_port}/sse", '
+            f'{{"type": "sse", "url": "{sse_url}", '
             f'"headers": {{"Authorization": "Bearer {t.token}"}}}}'
         )
         print(f"  claude mcp add-json grist-{t.name} '{config}'")

src/grist_mcp/tools/session.py

@@ -7,6 +7,7 @@ from grist_mcp.session import SessionTokenManager
 PROXY_DOCUMENTATION = {
     "description": "HTTP proxy API for bulk data operations. Use request_session_token to get a short-lived token, then call the proxy endpoint directly from scripts.",
     "endpoint": "POST /api/v1/proxy",
+    "endpoint_note": "The full URL is returned in the 'proxy_url' field of request_session_token response",
     "authentication": "Bearer token in Authorization header",
     "request_format": {
         "method": "Operation name (required)",
@@ -88,11 +89,12 @@ PROXY_DOCUMENTATION = {
 import requests
 import sys
 
+# Use token and proxy_url from request_session_token response
 token = sys.argv[1]
-host = sys.argv[2]
+proxy_url = sys.argv[2]
 
 response = requests.post(
-    f'{host}/api/v1/proxy',
+    proxy_url,
     headers={'Authorization': f'Bearer {token}'},
     json={
         'method': 'add_records',