# TinyFailureEvent / First Signal Event Pattern

## Module
Web

## Status
VERIFIED

## Description
First signal event UI is implemented with a dedicated store, typed models, and card components that surface first-run signal status in run detail and console status views.

## Implementation Details
- **Feature directory**: `src/Web/StellaOps.Web/src/app/features/runs/`
- **Components**:
  - `first-signal-card` (`src/Web/StellaOps.Web/src/app/features/runs/components/first-signal-card/first-signal-card.component.ts`)
  - Run detail integration (`src/Web/StellaOps.Web/src/app/features/release-orchestrator/runs/pipeline-run-detail.component.ts`)
  - Console status integration (`src/Web/StellaOps.Web/src/app/features/console/console-status.component.html`)
- **Services**:
  - `first-signal-prefetch` (`src/Web/StellaOps.Web/src/app/features/runs/services/first-signal-prefetch.service.ts`)
  - `first-signal.store` (`src/Web/StellaOps.Web/src/app/core/api/first-signal.store.ts`)
- **Behavior coverage**:
  - `src/Web/StellaOps.Web/src/tests/runs/firstsignalcard-component.component.spec.ts`
- **Source**: Feature matrix scan (naming normalized during QA verification)

## E2E Test Plan
- **Setup**:
  - [ ] Log in with a user that has appropriate permissions
  - [ ] Navigate to pipeline run detail or console status views
  - [ ] Ensure run data exists with first-signal snapshots/events
- **Core verification**:
  - [ ] Verify first-signal card renders deterministic state and metadata for a signal event
  - [ ] Verify telemetry hooks emit TTFS start/render events with stable payload fields
  - [ ] Verify retry interaction reissues first-signal load request
- **Edge cases**:
  - [ ] Verify graceful handling when backend API is unavailable (error/offline states)
  - [ ] Verify fallback when first signal is unavailable yet response metadata exists
  - [ ] Verify accessibility semantics (`role`, `aria-live`, busy/error states)

## Verification
- Run ID: `docs/qa/feature-checks/runs/web/tinyfailureevent-first-signal-event-pattern/run-001/`
- Date (UTC): 2026-02-11
- Tier 0: PASS (source/symbol verification for first-signal card/store/prefetch plus run-detail and console integrations).
- Tier 1: PASS (`npm run test` focused suite: 19 files / 94 tests; `npm run build` passed with known baseline warnings).
- Tier 2: PASS (behavioral verification of TTFS telemetry emission, retry path behavior, user-surface integrations, and removal of deprecated `allowSignalWrites` usage).