feat(gateway,storage): mosaic gateway doctor with tier health JSON (FED-M1-06) (#475)

packages/mosaic/src/commands/gateway.ts

@@ -206,4 +206,15 @@ export function registerGatewayCommand(program: Command): void {
       const { runUninstall } = await import('./gateway/uninstall.js');
       await runUninstall();
     });
+
+  // ─── doctor ─────────────────────────────────────────────────────────────────
+
+  gw.command('doctor')
+    .description('Check gateway tier and per-service health (PG, Valkey, pgvector)')
+    .option('--json', 'Emit TierHealthReport as JSON to stdout (suppresses all other output)')
+    .option('--config <path>', 'Path to mosaic.config.json (defaults to cwd or ~/.mosaic/)')
+    .action(async (cmdOpts: { json?: boolean; config?: string }) => {
+      const { runGatewayDoctor } = await import('./gateway-doctor.js');
+      await runGatewayDoctor({ json: cmdOpts.json, config: cmdOpts.config });
+    });
 }