refactor: auto-migrate legacy config in gateway

src/gateway/server.ts

@@ -48,6 +48,7 @@ import {
   CONFIG_PATH_CLAWDIS,
   isNixMode,
   loadConfig,
+  migrateLegacyConfig,
   parseConfigJson5,
   readConfigFileSnapshot,
   STATE_DIR_CLAWDIS,
@@ -1322,6 +1323,31 @@ export async function startGatewayServer(
   port = 18789,
   opts: GatewayServerOptions = {},
 ): Promise<GatewayServer> {
+  const configSnapshot = await readConfigFileSnapshot();
+  if (configSnapshot.legacyIssues.length > 0) {
+    if (isNixMode) {
+      throw new Error(
+        "Legacy config entries detected while running in Nix mode. Update your Nix config to the latest schema and restart.",
+      );
+    }
+    const { config: migrated, changes } = migrateLegacyConfig(
+      configSnapshot.parsed,
+    );
+    if (!migrated) {
+      throw new Error(
+        "Legacy config entries detected but auto-migration failed. Run \"clawdis doctor\" to migrate.",
+      );
+    }
+    await writeConfigFile(migrated);
+    if (changes.length > 0) {
+      log.info(
+        `gateway: migrated legacy config entries:\n${changes
+          .map((entry) => `- ${entry}`)
+          .join("\n")}`,
+      );
+    }
+  }
+
   const cfgAtStart = loadConfig();
   const bindMode = opts.bind ?? cfgAtStart.gateway?.bind ?? "loopback";
   const bindHost = opts.host ?? resolveGatewayBindHost(bindMode);