feat(tess): add safe runtime observability (#726)

apps/gateway/src/agent/providers.controller.ts

@@ -33,7 +33,20 @@ export class ProvidersController {
 
   @Get('health')
   health() {
-    return { providers: this.providerService.getProvidersHealth() };
+    return { providers: this.safeProviderHealth() };
+  }
+
+  /**
+   * Safe operational status for troubleshooting and readiness checks. Provider
+   * errors are reduced to a stable code so credentials and remote responses
+   * cannot leak through this endpoint.
+   */
+  @Get('status')
+  status() {
+    return {
+      providers: this.safeProviderHealth(),
+      effectivePolicy: this.providerService.getEffectivePolicyStatus(),
+    };
   }
 
   @Post('test')
@@ -51,6 +64,13 @@ export class ProvidersController {
     return this.routingService.rank(criteria);
   }
 
+  private safeProviderHealth() {
+    return this.providerService.getProvidersHealth().map(({ error, ...provider }) => ({
+      ...provider,
+      ...(error ? { errorCode: 'provider_unavailable' } : {}),
+    }));
+  }
+
   // ── Credential CRUD ──────────────────────────────────────────────────────
 
   /**