docs: update documentation to OKF v0.1 format

docs/architecture/key-files.md

@@ -3,7 +3,7 @@ type: architecture
 title: Key Files Index
 description: One-line responsibility for important source and contract-test files, including event-window, challenge, scoreboard, session, notification, and blog flows.
 tags: [architecture, key-files, event-window, validation, default-challenge-ip, sse, bootstrap, migrations, challenges, import, board, notifications, per-user, session, blog]
-timestamp: 2026-07-23T13:27:25Z
+timestamp: 2026-07-23T15:46:55Z
 ---
 
 # Backend
@@ -13,8 +13,9 @@ timestamp: 2026-07-23T13:27:25Z
 | `backend/src/main.ts` | Bootstraps Nest, middleware, OpenAPI, static assets, and SPA fallback. |
 | `backend/src/app.module.ts` | Wires feature modules and global providers. |
 | `backend/src/config/env.schema.ts` | Zod-validated runtime config; canonical defaults for `DATABASE_PATH` (`./data/db.sqlite`) and `UPLOAD_DIR` (`./data/uploads`). |
-| `backend/src/database/database.module.ts` | Configures TypeORM with SQLite. |
-| `backend/src/database/database-init.service.ts` | Initializes the database and runs migrations; `verifySeed()` also asserts the canonical six system-category keys and reports missing/duplicate rows. |
+| `backend/src/database/database.module.ts` | Configures TypeORM with SQLite and imports the shared `FilesystemTransactionModule` used by pre-TypeORM startup recovery. |
+| `backend/src/database/database-init.service.ts` | Before opening SQLite, resolves durable swap manifests to a coherent old or verified-new database/uploads generation, fails startup closed on ambiguity, best-effort sweeps stale unowned swap artifacts, then runs migrations, enforces WAL, and verifies seeds. |
+| `backend/src/modules/admin/system/filesystem-transaction.module.ts` | Exports one shared `FilesystemTransactionService` provider to `DatabaseModule` and `AdminSystemModule`, avoiding a circular dependency. |
 | `backend/src/database/migrations/1700000000400-RepairCategorySchemaAndSystemCategories.ts` | Forward-only repair migration: adds `created_at`/`updated_at` to legacy six-column `category` tables, deletes obsolete `FOR`/`OSI` system rows, rewrites canonical row metadata, inserts any missing canonical key, and re-asserts unique indexes. Exports `CANONICAL_SYSTEM_CATEGORIES`. |
 | `backend/src/common/guards/jwt-auth.guard.ts` | Global JWT authorization guard. |
 | `backend/src/common/middleware/csrf.middleware.ts` | Double-submit CSRF protection. |
@@ -124,11 +125,11 @@ timestamp: 2026-07-23T13:27:25Z
 | `tests/frontend/scoreboard.pure.spec.ts` | Pure helpers: `applyRankingSort` (competition-rank numbering), `parseSolveEventIntoRanking` (add-or-increment + sort), `dedupEventLogBySolveId`, `applySolveToGraph` (anchors + plateau + top-10 trim), `mutateMatrixFromSolve`, `stablePlayerColorIndex`, `formatSolveDateTime`. |
 | `tests/frontend/scoreboard.store.spec.ts` | Store lifecycle + live merge: `loadAll` aggregation + idempotency, SSE `solve` frame applying to all four tabs, `stop()` teardown, exponential reconnect. |
 | `backend/src/modules/admin/system/admin-system.controller.ts` | Mounts `/api/v1/admin/system/*` (backup download, restore validate/commit, confirmations, scores/reset, challenges/wipe); all handlers require `AdminGuard` + `@Roles('admin')` and the destructive ones also consume a confirmation token. |
-| `backend/src/modules/admin/system/admin-system.module.ts` | Wires `AdminSystemController`, `BackupService`, `RestoreService`, `DangerZoneService`, `FilesystemTransactionService`, `ConfirmationTokenService`; imports `TypeOrmModule.forFeature([AdminOperationTokenEntity])` and `AuthModule`. |
+| `backend/src/modules/admin/system/admin-system.module.ts` | Wires `AdminSystemController`, `BackupService`, `RestoreService`, `DangerZoneService`, and `ConfirmationTokenService`; imports the shared `FilesystemTransactionModule`, `TypeOrmModule.forFeature([AdminOperationTokenEntity])`, and `AuthModule`. |
 | `backend/src/modules/admin/system/backup.service.ts` | Builds the full backup JSON: every application table (`sqlite_master` discovery, excluding `admin_operation_token`/`migrations`/`sqlite_*`), with base64-encoded uploads walked recursively from `UPLOAD_DIR` (skipping `.staging`). Exposes `discoverTables()`, `getUploadDir()`, and `BackupService.stringify(doc)`. |
-| `backend/src/modules/admin/system/restore.service.ts` | Two-phase restore: `stageArchive(rawText, userId)` validates the archive (zod), decodes uploads into `<DATA_DIR>/.system-staging/restore-<id>/`, and returns a summary; `commitRestore(stagingId)` clones the live DB, captures and temporarily drops the `trg_user_last_admin_update` / `trg_user_last_admin_delete` triggers in the offline candidate, clears every application table, re-inserts archived rows in FK-safe order, asserts the archive still contains at least one admin, re-creates the captured triggers, then atomically swaps the live DB + uploads via `FilesystemTransactionService.stageSwap({ name: 'restore-backup', ... })`. On any failure the swap is rolled back and `SYSTEM_RESTORE_ROLLED_BACK` is returned; the rebuild also best-effort re-creates any missing trigger before rethrowing so a rolled-back candidate never leaks missing the `LAST_ADMIN` safety net. |
+| `backend/src/modules/admin/system/restore.service.ts` | Two-phase restore: validates/stages the archive, rebuilds an offline SQLite candidate while preserving the last-admin triggers, then swaps database + uploads as one durable manifest-backed generation; tracks SQLite `-wal`/`-shm` sidecars and reconnects TypeORM only after verification. |
 | `backend/src/modules/admin/system/danger-zone.service.ts` | `resetScores()` deletes every `solve` row transactionally; `wipeChallenges()` snapshots `<UPLOAD_DIR>/challenges` to a side directory, deletes every challenge inside a transaction, physically removes the live `-challenges` directory post-commit, and either deletes the snapshot or restores from it on failure. |
-| `backend/src/modules/admin/system/filesystem-transaction.service.ts` | Generic file/directory swap primitive: `stageSwap({ pairs, hooks })` renames each live path to a rollback location, then renames the staged path into place (with copy+unlink cross-device fallback); `commit(handle)` removes rollback artifacts; `rollback(handle)` restores the original live paths. Provides static helpers `rmSafe`, `copyDirSync`, `ensureDir`. |
+| `backend/src/modules/admin/system/filesystem-transaction.service.ts` | Crash-safe multi-path swap primitive. Persists per-transaction phase/path manifests under `SYSTEM_OP_STAGING_DIR`, moves configured sidecars with their generation, commits or rolls back idempotently, restores a complete old generation after an interrupted snapshot, finalizes a complete verified new generation, fails closed on mixed/ambiguous state, and sweeps stale unowned rollback/restore/wipe artifacts. |
 | `backend/src/modules/admin/system/confirmation-token.service.ts` | Issues SHA-256-hashed single-use tokens with `SYSTEM_OP_CONFIRM_TOKEN_TTL_MS` TTL; `consume()` runs in a transaction with conditional `WHERE consumedAt IS NULL` updates so only the first concurrent caller succeeds. `purgeExpired()` deletes expired and >24h-old consumed rows. |
 | `backend/src/modules/admin/system/dto/admin-system.dto.ts` | Re-exports `ADMIN_OPERATION_KINDS` and zod contracts for the re-auth body, danger confirm body, and restore-commit body; declares the backup format identifier + version constants. |
 | `backend/src/database/entities/admin-operation-token.entity.ts` | TypeORM entity and the canonical `ADMIN_OPERATION_KINDS` literal union (`restore-backup`, `reset-scores`, `wipe-challenges`). |
@@ -142,7 +143,9 @@ timestamp: 2026-07-23T13:27:25Z
 | `tests/backend/admin-system-confirmation-token.spec.ts` | Issue/consume/expire/reuse/mismatch flow and TTL config. |
 | `tests/backend/admin-system-danger.spec.ts` | Reset-scores and wipe-challenges happy path + DB/file rollback. |
 | `tests/backend/admin-system-restore-validation.spec.ts` | Archive schema validation, base64 size mismatch, sha256 mismatch, safe-path rejection, and duplicate-path rejection. |
-| `tests/backend/admin-system-restore-commit.spec.ts` | Controller forwards `stagingId` to `RestoreService.commitRestore`, plus a real-file service-level regression that restores a backup containing the same admin as the live system, asserts swapped table settings + uploads + trigger preservation, and verifies an admin-less archive is rejected with `SYSTEM_RESTORE_ROLLED_BACK`. |
+| `tests/backend/admin-system-restore-commit.spec.ts` | Controller forwarding, real-file restore, trigger preservation, admin-less archive rejection, and kill-during-swap regression proving restart recovers one coherent database/uploads generation. |
+| `tests/backend/database-init-recovery.spec.ts` | Startup recovery contracts: restores old generations from interrupted manifests, fails closed without mutation on hybrid state, and removes stale unowned artifacts. |
+| `tests/backend/filesystem-transaction.spec.ts` | Durable manifest phase, commit/rollback, old/new generation recovery, ambiguous fail-closed, and stale artifact sweep contracts. |
 | `frontend/src/app/features/admin/system/system.component.ts` | `/admin/system` smart page: two panels (Database + Danger Zone), backup download, restore pick + validate, confirm modal trigger, and per-operation success/error surfacing + cross-store invalidation. |
 | `frontend/src/app/features/admin/system/system-confirm-modal.component.ts` | Re-authentication + confirmation-phrase modal with operation-specific copy from `system.pure.ts`. |
 | `frontend/src/app/features/admin/system/system.service.ts` | HTTP client for the six `/api/v1/admin/system/*` endpoints. |