AI Implementation feature(907): Challenges Page and Challenge Solve Modal 1.03 (#49)

docs/architecture/frontend-structure.md

@@ -89,7 +89,7 @@ single path.
 | `EventState` | Union `'running' \| 'countdown' \| 'stopped' \| 'unconfigured'`. |
 | `EventStatePayload` | Server-pushed event window payload shape. |
 | `EventSourceLike` | Minimal interface for any SSE transport the store can drive. |
-| `formatDdHhMm(seconds)` | Pure `DD:HH:mm` formatter. |
+| `formatDdHhMm(seconds)` | Pure `DD:HH:mm:ss` formatter (zero-padded, falls back to `00:00:00:00` for negative / non-finite input). |
 | `deriveCountdownText(state, start, end)` | Pure mapping from event window state to countdown label. |
 | `LED_COLOR_BY_STATE` | `Readonly<Record<EventState, string>>` mapping each state to its theme CSS variable (`var(--color-success)`, `--color-warning`, `--color-danger`, `--color-secondary`). |
 | `ledBackgroundColor(state)` | Pure accessor returning the `background-color` value for the LED element. |

docs/architecture/key-files.md

@@ -59,7 +59,7 @@ timestamp: 2026-07-23T01:19:00Z
 | `frontend/src/app/core/services/bootstrap-event.service.ts` | Root-provided public SSE listener that subscribes to `/api/v1/event/stream`, filters `topic === 'general'` frames, and triggers `BootstrapService.refresh()` so the landing modal stays in sync with admin general-settings updates. |
 | `frontend/src/app/core/services/bootstrap-event.pure.ts` | Pure helpers for the public bootstrap SSE listener: `isBootstrapGeneralFrame` predicate, SSE line parser, and the `makeBootstrapEventSource` factory (fetch + `ReadableStream` opener with frame buffering and idempotent `close()`). |
 | `frontend/src/app/core/services/event-status.store.ts` | Event state signal store, one-second countdown timer, and the optional `onUnauthorized` callback wiring; exposes `start()`/`stop()`/`closeTransport()` for transport lifecycle and `subscribeReloadAtCountdownZero(handler)` (with `reloadAtCountdownZero(handler)` kept as a back-compat wrapper) so the reload handler is owned by its subscriber rather than the transport. |
-| `frontend/src/app/core/services/event-status.pure.ts` | Event payload types, transport interface (including `'unauthorized'` listener), pure countdown helpers, and the `LED_COLOR_BY_STATE` map used by the shell LED. |
+| `frontend/src/app/core/services/event-status.pure.ts` | Event payload types, transport interface (including `'unauthorized'` listener), pure countdown helpers (`formatDdHhMm` returns `DD:HH:mm:ss` and `deriveCountdownText`), and the `LED_COLOR_BY_STATE` map used by the shell LED. |
 | `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services, subscribes to peer invalidation, and navigates to `/login` when the session is invalidated elsewhere. |
 | `frontend/src/app/features/shell/header/shell-header.component.ts` | Shell title, status LED (size/shape only — color comes from the pure map via `[style.background-color]`), countdown, and user menu. |
 | `frontend/src/app/features/shell/tabs/quick-tabs.component.ts` | Main shell navigation tabs. |
@@ -74,14 +74,15 @@ timestamp: 2026-07-23T01:19:00Z
 | `tests/frontend/admin-challenges-import-autoclose.spec.ts` | Pure helpers (`summarizeImportResult`, `importErrorMessage`) and modal auto-close branch for the confirmed-import handler. |
 | `frontend/src/app/features/challenges/challenges.page.ts` | `/challenges` smart page: gate logic (countdown/running/stopped/unconfigured), modal lifecycle, SSE wiring on `/api/v1/events`, and the page-owned countdown-zero reload (handler registered in the constructor with the disposer wired into `DestroyRef`). |
 | `frontend/src/app/features/challenges/challenges.store.ts` | Signal store: board, event state, per-card solve listeners, SSE solve-frame mutation, submit response application, stop() lifecycle. |
-| `frontend/src/app/features/challenges/challenges.service.ts` | HTTP service for `/api/v1/challenges/{board,status,:id,:id/solves}` returning typed `ApiErrorEnvelope`s. |
+| `frontend/src/app/features/challenges/challenges.service.ts` | HTTP service for `/api/v1/challenges/{board,status,:id,:id/solves}` returning typed `ApiErrorEnvelope`s. `getDetail` always requests `?include=solvers` so the modal can render the solvers list in one round-trip; `getBoard` only attaches `include=solvers` when the caller opts in. |
 | `frontend/src/app/features/challenges/challenges.pure.ts` | Pure types and helpers (`BoardCard`, `SolverRow`, `SolveEventPayload`, `parseSolveEvent`, `mergeSolveEventIntoSolvers`, `messageForSolveError`, `formatDdHhMm`). |
 | `frontend/src/app/features/challenges/category-column.component.ts` | Renders a single category column (header + cards) on the challenges board. |
 | `frontend/src/app/features/challenges/challenge-card.component.ts` | Renders a single challenge card on the board (difficulty, live points, solve count, `✓` when solved by the player). |
 | `frontend/src/app/features/challenges/challenge-modal.component.ts` | Challenge detail modal: description, flag form, awarded banner, solvers list, live-solve updates. |
 | `frontend/src/app/core/services/notification.service.ts` | Root-provided signal-backed store of `{ id, kind, message, ts }` records; `error()` / `info()` push, `dismiss(id)` / `clear()` remove. |
 | `frontend/src/app/core/interceptors/error-notification.interceptor.ts` | Translates `HttpErrorResponse` into friendly messages and pushes them to `NotificationService` (with suppression for `/api/v1/auth/{login,csrf,register}` and `/api/v1/challenges/status`). |
-| `tests/frontend/challenges.pure.spec.ts` | Pure helpers: sorting, parsers, friendly error mapping, `formatDdHhMm`. |
+| `tests/frontend/challenges.pure.spec.ts` | Pure helpers: sorting, parsers, friendly error mapping, `formatDdHhMm` (`DD:HH:mm:ss`). |
+| `tests/frontend/challenges.service.spec.ts` | HTTP-service contract: `getDetail` URL-encodes the id, attaches `?include=solvers`, and forwards `withCredentials: true`. |
 | `tests/frontend/challenges.store.spec.ts` | Signal store: board mutation, live solve merge, listeners, `stop()`. |
 | `tests/frontend/notification-interceptor.spec.ts` | Interceptor suppression rules and friendly message mapping. |
 | `tests/backend/challenges-board.spec.ts` | Board query shape, ordering, `?include=solvers`. |