feat(uba): UBA-008/009 panel registration + health indicator

UBA-008: Register UBAPanel in editor sidebar (router.setup.ts)
UBA-009: Health indicator widget in Configure tab
  - useUBAHealth hook polling UBAClient.health() every 30s
  - HealthBadge component: 4 states (unknown/checking/healthy/unhealthy)
  - Pulsing animation on checking; design token colours with fallbacks
  - Shown only when schema.backend.endpoints.health is present

Test fix: UBASchemaParser.test.ts
  - isFailure<T>() type guard for webpack ts-loader friendly narrowing
  - eslint-disable for destructuring discard patterns

dev-docs/tasks/phase-6-uba-system/PROGRESS-richard.md

@@ -49,8 +49,41 @@
 | UBA-006 ConfigPanel mounting | ✅ Done | UBAPanel with project metadata   |
 | UBA-007 Debug Stream Panel   | ✅ Done | SSE viewer in Debug tab          |
 
+### Session 4 (Sprint 2)
+
+- **UBA-008**: `router.setup.ts` — Registered UBAPanel in editor sidebar
+
+  - Added `uba` route with `UBAPanel` component
+  - Panel accessible via editor sidebar navigation
+
+- **UBA-009**: `UBAPanel.tsx` + `UBAPanel.module.scss` — Health indicator widget
+
+  - `useUBAHealth` hook: polls `UBAClient.health()` every 30s, never throws
+  - `HealthBadge` component: dot + label, 4 states (unknown/checking/healthy/unhealthy)
+  - Animated pulse on `checking` state; green/red semantic colours with `--theme-color-success/danger` tokens + fallbacks
+  - Shown above ConfigPanel when `schema.backend.endpoints.health` is present
+  - `configureTabContent` wrapper div for flex layout
+
+- **Test fixes**: `UBASchemaParser.test.ts`
+  - Added `isFailure<T>()` type guard (webpack ts-loader friendly discriminated union narrowing)
+  - Replaced all `if (!result.success)` with `if (isFailure(result))`
+  - Fixed destructuring discard pattern `_sv`/`_b` → `_` with `eslint-disable-next-line`
+
+## Status
+
+| Task                         | Status  | Notes                            |
+| ---------------------------- | ------- | -------------------------------- |
+| UBA-001 Types                | ✅ Done |                                  |
+| UBA-002 SchemaParser         | ✅ Done | Instance method `.parse()`       |
+| UBA-003 Field Renderers      | ✅ Done | 8 field types                    |
+| UBA-004 ConfigPanel          | ✅ Done | Tabs, validation, dirty state    |
+| UBA-005 UBAClient            | ✅ Done | configure/health/openDebugStream |
+| UBA-006 ConfigPanel mounting | ✅ Done | UBAPanel with project metadata   |
+| UBA-007 Debug Stream Panel   | ✅ Done | SSE viewer in Debug tab          |
+| UBA-008 Panel registration   | ✅ Done | Sidebar route in router.setup.ts |
+| UBA-009 Health indicator     | ✅ Done | useUBAHealth + HealthBadge       |
+
 ## Next Up
 
-- UBA-008: UBA panel registration in editor sidebar
-- UBA-009: UBA health indicator / status widget
 - STYLE tasks: Any remaining style overhaul items
+- UBA-010: Consider E2E integration test with mock backend

packages/noodl-editor/src/editor/src/router.setup.ts

@@ -27,6 +27,7 @@ import { PropertyEditor } from './views/panels/propertyeditor';
 import { SearchPanel } from './views/panels/search-panel/search-panel';
 // import { TopologyMapPanel } from './views/panels/TopologyMapPanel'; // Disabled - shelved feature
 import { TriggerChainDebuggerPanel } from './views/panels/TriggerChainDebuggerPanel';
+import { UBAPanel } from './views/panels/UBAPanel';
 import { UndoQueuePanel } from './views/panels/UndoQueuePanel/UndoQueuePanel';
 import { VersionControlPanel_ID } from './views/panels/VersionControlPanel';
 import { VersionControlPanel } from './views/panels/VersionControlPanel/VersionControlPanel';
@@ -167,6 +168,17 @@ export function installSidePanel({ isLesson }: SetupEditorOptions) {
     panel: AppSetupPanel
   });
 
+  SidebarModel.instance.register({
+    experimental: true,
+    id: 'uba',
+    name: 'Backend Adapter',
+    description: 'Configure and debug Universal Backend Adapter (UBA) compatible backends via schema-driven forms.',
+    isDisabled: isLesson === true,
+    order: 8.8,
+    icon: IconName.RestApi,
+    panel: UBAPanel
+  });
+
   SidebarModel.instance.register({
     id: 'settings',
     name: 'Project settings',

packages/noodl-editor/src/editor/src/views/panels/UBAPanel/UBAPanel.module.scss

@@ -306,3 +306,88 @@
     color: var(--theme-color-primary);
   }
 }
+
+// ─── Health Indicator (UBA-009) ───────────────────────────────────────────────
+
+.configureTabContent {
+  display: flex;
+  flex-direction: column;
+  flex: 1;
+  overflow: hidden;
+}
+
+.healthBadge {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 5px 10px;
+  border-bottom: 1px solid var(--theme-color-border-default);
+  background: var(--theme-color-bg-2);
+  flex-shrink: 0;
+}
+
+.healthDot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  flex-shrink: 0;
+  background: var(--theme-color-fg-default-shy);
+}
+
+.healthLabel {
+  font-size: 11px;
+  color: var(--theme-color-fg-default-shy);
+}
+
+// Status modifier classes — applied to .healthBadge
+.healthUnknown {
+  .healthDot {
+    background: var(--theme-color-fg-default-shy);
+  }
+
+  .healthLabel {
+    color: var(--theme-color-fg-default-shy);
+  }
+}
+
+.healthChecking {
+  .healthDot {
+    background: var(--theme-color-fg-default);
+    animation: healthPulse 1s ease-in-out infinite;
+  }
+
+  .healthLabel {
+    color: var(--theme-color-fg-default);
+  }
+}
+
+.healthHealthy {
+  .healthDot {
+    background: var(--theme-color-success, #4ade80);
+  }
+
+  .healthLabel {
+    color: var(--theme-color-success, #4ade80);
+  }
+}
+
+.healthUnhealthy {
+  .healthDot {
+    background: var(--theme-color-danger, #f87171);
+  }
+
+  .healthLabel {
+    color: var(--theme-color-danger, #f87171);
+  }
+}
+
+@keyframes healthPulse {
+  0%,
+  100% {
+    opacity: 1;
+  }
+
+  50% {
+    opacity: 0.4;
+  }
+}

packages/noodl-editor/src/editor/src/views/panels/UBAPanel/UBAPanel.tsx

@@ -38,6 +38,79 @@ import css from './UBAPanel.module.scss';
 
 const METADATA_SCHEMA_URL = 'ubaSchemaUrl';
 const METADATA_CONFIG = 'ubaConfig';
+const HEALTH_POLL_INTERVAL_MS = 30_000;
+
+// ─── Health Indicator (UBA-009) ───────────────────────────────────────────────
+
+type HealthStatus = 'unknown' | 'checking' | 'healthy' | 'unhealthy';
+
+/**
+ * Polls the backend health endpoint every 30s.
+ * Uses UBAClient.health() which never throws.
+ */
+function useUBAHealth(
+  healthUrl: string | undefined,
+  auth: UBASchema['backend']['auth'] | undefined
+): { status: HealthStatus; message: string | undefined } {
+  const [status, setStatus] = useState<HealthStatus>('unknown');
+  const [message, setMessage] = useState<string | undefined>();
+
+  useEffect(() => {
+    if (!healthUrl) {
+      setStatus('unknown');
+      setMessage(undefined);
+      return;
+    }
+
+    let cancelled = false;
+
+    const check = async () => {
+      if (!cancelled) setStatus('checking');
+      const result = await UBAClient.health(healthUrl, auth);
+      if (!cancelled) {
+        setStatus(result.healthy ? 'healthy' : 'unhealthy');
+        setMessage(result.healthy ? undefined : result.message);
+      }
+    };
+
+    void check();
+    const timer = setInterval(() => void check(), HEALTH_POLL_INTERVAL_MS);
+    return () => {
+      cancelled = true;
+      clearInterval(timer);
+    };
+  }, [healthUrl, auth]);
+
+  return { status, message };
+}
+
+const HEALTH_STATUS_CLASS: Record<HealthStatus, string> = {
+  unknown: css.healthUnknown,
+  checking: css.healthChecking,
+  healthy: css.healthHealthy,
+  unhealthy: css.healthUnhealthy
+};
+
+const HEALTH_STATUS_LABEL: Record<HealthStatus, string> = {
+  unknown: 'Not configured',
+  checking: 'Checking…',
+  healthy: 'Healthy',
+  unhealthy: 'Unhealthy'
+};
+
+interface HealthBadgeProps {
+  status: HealthStatus;
+  message: string | undefined;
+}
+
+function HealthBadge({ status, message }: HealthBadgeProps) {
+  return (
+    <div className={`${css.healthBadge} ${HEALTH_STATUS_CLASS[status]}`} title={message ?? HEALTH_STATUS_LABEL[status]}>
+      <span className={css.healthDot} aria-hidden="true" />
+      <span className={css.healthLabel}>{HEALTH_STATUS_LABEL[status]}</span>
+    </div>
+  );
+}
 
 // ─── Schema Loader ────────────────────────────────────────────────────────────
 
@@ -208,6 +281,8 @@ export function UBAPanel() {
     [schema]
   );
 
+  const health = useUBAHealth(schema?.backend.endpoints.health, schema?.backend.auth);
+
   const renderConfigureTab = () => {
     if (!schemaUrl && !loading) {
       return <SchemaLoader onLoad={loadSchema} loading={loading} error={loadError} />;
@@ -233,14 +308,17 @@ export function UBAPanel() {
     }
 
     return (
-      <ConfigPanel
-        schema={schema}
-        initialValues={getSavedConfig()}
-        onSave={handleSave}
-        onReset={() => {
-          /* noop — reset is handled inside ConfigPanel */
-        }}
-      />
+      <div className={css.configureTabContent}>
+        {schema.backend.endpoints.health && <HealthBadge status={health.status} message={health.message} />}
+        <ConfigPanel
+          schema={schema}
+          initialValues={getSavedConfig()}
+          onSave={handleSave}
+          onReset={() => {
+            /* noop — reset is handled inside ConfigPanel */
+          }}
+        />
+      </div>
     );
   };
 

packages/noodl-editor/tests/models/UBASchemaParser.test.ts

@@ -9,6 +9,12 @@
 import { describe, it, expect, beforeEach } from '@jest/globals';
 
 import { SchemaParser } from '../../src/editor/src/models/UBA/SchemaParser';
+import type { ParseResult } from '../../src/editor/src/models/UBA/types';
+
+/** Type guard: narrows ParseResult to the failure branch (webpack ts-loader friendly) */
+function isFailure<T>(result: ParseResult<T>): result is Extract<ParseResult<T>, { success: false }> {
+  return !result.success;
+}
 
 // ─── Fixtures ─────────────────────────────────────────────────────────────────
 
@@ -44,7 +50,7 @@ describe('SchemaParser', () => {
     it('rejects null input', () => {
       const result = parser.parse(null);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors[0].path).toBe('');
       }
     });
@@ -55,10 +61,11 @@ describe('SchemaParser', () => {
     });
 
     it('rejects missing schema_version', () => {
-      const { schema_version: _sv, ...noVersion } = minimalValid;
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      const { schema_version: _, ...noVersion } = minimalValid;
       const result = parser.parse(noVersion);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors.some((e) => e.path === 'schema_version')).toBe(true);
       }
     });
@@ -87,10 +94,11 @@ describe('SchemaParser', () => {
 
   describe('backend validation', () => {
     it('errors when backend is missing', () => {
-      const { backend: _b, ...noBackend } = minimalValid;
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      const { backend: _, ...noBackend } = minimalValid;
       const result = parser.parse(noBackend);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors.some((e) => e.path === 'backend')).toBe(true);
       }
     });
@@ -107,7 +115,7 @@ describe('SchemaParser', () => {
       });
       const result = parser.parse(data);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors.some((e) => e.path === 'backend.endpoints.config')).toBe(true);
       }
     });
@@ -138,7 +146,7 @@ describe('SchemaParser', () => {
       });
       const result = parser.parse(data);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors.some((e) => e.path === 'backend.auth.type')).toBe(true);
       }
     });
@@ -171,7 +179,7 @@ describe('SchemaParser', () => {
       });
       const result = parser.parse(data);
       expect(result.success).toBe(false);
-      if (!result.success) {
+      if (isFailure(result)) {
         expect(result.errors.some((e) => e.path.includes('id'))).toBe(true);
       }
     });