feat: auto-derive oidc.discovery_url from NEXTCLOUD_HOST

When OIDC_DISCOVERY_URL is not explicitly set, the status endpoint now
auto-derives the discovery URL from NEXTCLOUD_HOST using the standard
well-known path. This allows Astrolabe to discover OIDC endpoints
without requiring explicit OIDC configuration.

The oidc block is now included in the status response regardless of
auth mode when a discovery URL is available (explicit or derived),
enabling smoother auth mode transitions.

Closes #1

nextcloud_mcp_server/api/management.py

@@ -235,24 +235,26 @@ async def get_server_status(request: Request) -> JSONResponse:
     if mode == AuthMode.MULTI_USER_BASIC:
         response_data["supports_app_passwords"] = settings.enable_offline_access
 
-    # Include OIDC configuration if OAuth is available
-    # This includes OAuth mode AND hybrid mode (multi_user_basic + offline_access)
-    # Astrolabe needs OIDC config to discover IdP for OAuth flow in hybrid mode
-    oauth_provisioning_available = auth_mode == "oauth" or (
-        mode == AuthMode.MULTI_USER_BASIC and settings.enable_offline_access
-    )
-    if oauth_provisioning_available:
-        # Provide IdP discovery information for NC PHP app
-        oidc_config = {}
+    # Include OIDC configuration for client discovery (e.g. Astrolabe PHP app).
+    # Always attempt to provide oidc.discovery_url so clients can discover the
+    # IdP regardless of the current auth mode. This enables smoother transitions
+    # between auth modes and lets Astrolabe pre-discover OIDC endpoints.
+    oidc_config: dict[str, str] = {}
 
-        if settings.oidc_discovery_url:
-            oidc_config["discovery_url"] = settings.oidc_discovery_url
+    if settings.oidc_discovery_url:
+        # Explicit OIDC_DISCOVERY_URL takes precedence
+        oidc_config["discovery_url"] = settings.oidc_discovery_url
+    elif settings.nextcloud_host:
+        # Auto-derive from NEXTCLOUD_HOST — Nextcloud exposes OIDC discovery
+        # at the standard well-known path when user_oidc is enabled
+        host = settings.nextcloud_host.rstrip("/")
+        oidc_config["discovery_url"] = f"{host}/.well-known/openid-configuration"
 
-        if settings.oidc_issuer:
-            oidc_config["issuer"] = settings.oidc_issuer
+    if settings.oidc_issuer:
+        oidc_config["issuer"] = settings.oidc_issuer
 
-        if oidc_config:
-            response_data["oidc"] = oidc_config
+    if oidc_config:
+        response_data["oidc"] = oidc_config
 
     return JSONResponse(response_data)