docs: update documentation to OKF v0.1 format

docs/architecture/key-files.md

@@ -1,9 +1,9 @@
 ---
 type: architecture
 title: Key Files Index
-description: One-line responsibility for important source and contract-test files, including strict event-window validation, the public bootstrap SSE listener, the challenges full-replace import flow, and the authenticated player-facing challenges board.
-tags: [architecture, key-files, event-window, validation, default-challenge-ip, sse, bootstrap, migrations, challenges, import, board, notifications]
-timestamp: 2026-07-23T01:19:00Z
+description: One-line responsibility for important source and contract-test files, including strict event-window validation, the public bootstrap SSE listener, the challenges full-replace import flow, the authenticated player-facing challenges board, and the per-user `solvedByMe` reset on the session boundary.
+tags: [architecture, key-files, event-window, validation, default-challenge-ip, sse, bootstrap, migrations, challenges, import, board, notifications, per-user, session]
+timestamp: 2026-07-23T03:45:00Z
 ---
 
 # Backend
@@ -52,7 +52,7 @@ timestamp: 2026-07-23T01:19:00Z
 | `frontend/src/app/core/services/bootstrap.service.ts` | Caches and exposes bootstrap state, refreshes it after admin updates, and applies the resolved theme. |
 | `frontend/src/app/core/services/bootstrap.types.ts` | Defines bootstrap/theme payload types and maps theme tokens to CSS custom properties. |
 | `frontend/src/app/core/services/admin.service.ts` | Calls admin settings, theme-list, category, and upload APIs. |
-| `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services. |
+| `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services; on logout and on session invalidation also calls `challengesStore.reset()` to flush any per-user board cache before navigating to `/login`. |
 | `frontend/src/app/core/services/auth.service.ts` | Signal-backed access token and current-user state; owns the cross-tab invalidation `BroadcastChannel` + `storage`-event fallback. |
 | `frontend/src/app/core/services/auth-session-events.pure.ts` | Pure cross-tab message encoding/validation and namespaced constants used by the auth broadcast channel. |
 | `frontend/src/app/core/services/authenticated-event-source.service.ts` | Fetch-based authenticated SSE transport with frame parsing, abort support, and a separate `'unauthorized'` event for `401`/`403`. |
@@ -60,7 +60,7 @@ timestamp: 2026-07-23T01:19:00Z
 | `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 (`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/home/home.component.ts` | Authenticated shell container; starts user and event state services, subscribes to peer invalidation, resets both `UserStore` and `ChallengesStore`, 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. |
 | `frontend/src/app/features/shell/change-password/change-password-modal.component.ts` | Change-password form modal. |
@@ -73,7 +73,7 @@ timestamp: 2026-07-23T01:19:00Z
 | `tests/frontend/auth-session-events.spec.ts` | Pure tests for cross-tab invalidation message encoding, payload validation, and `storage`-event filtering. |
 | `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.store.ts` | Signal store: board, event state, per-card solve listeners, SSE solve-frame mutation, submit response application, stop() lifecycle, public `reset()` for the session-boundary flush, and `setMyUserId(id)` which now returns the previous id and clears the cache whenever the cached state belongs to an unknown or different user. |
 | `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. |
@@ -83,7 +83,8 @@ timestamp: 2026-07-23T01:19:00Z
 | `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` (`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/challenges.store.spec.ts` | Signal store: board mutation, live solve merge, listeners, `stop()`. The "marks solvedByMe" and "does not double-count" tests now call `setMyUserId('me-1')` *before* `load()` to exercise the realistic page-mount sequence. |
+| `tests/frontend/challenges.store.reset.spec.ts` | Per-user `solvedByMe` regression suite: `reset()` clears board/detail/myUserId/SSE; switching user id flushes the previous board; **orphan board** (cached with no recorded user id) is cleared when PlayerB's id is set; a non-mine solve never flips `solvedByMe` from `false` to `true`; `applySubmitResponse` takes the server value verbatim. |
 | `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`. |
 | `tests/backend/challenges-status-rest.spec.ts` | `/api/v1/challenges/status` snapshot shape. |