fix(user-flow): close offline-queue, export, session, ban & realtime gaps

Comprehensive user-flow review across guest/host/admin roles, then fixes with
e2e regression guards. Highlights:

- Offline upload queue auto-resumes on reconnect: network errors keep items
  pending (not error), 4xx are terminal (no infinite retry), quota exhaustion
  returns a distinct 413; queue cap + dedup.
- Export lifecycle: release atomically locks uploads; reopen invalidates and
  re-release regenerates the keepsake; workers claim their job atomically so a
  reopen->re-release can't corrupt the ZIP; startup re-spawns interrupted
  exports.
- Sessions slide on activity (no 30-day cliff); JWT expiry deferred to the
  revocable session row; sign-out-everywhere + revoke-on-PIN-reset.
- Ban always hides content (v_feed / find_visible_media / export filter
  is_banned) but stays a read-only ban per USER_JOURNEYS §10 — sessions are
  not revoked, read access + keepsake download preserved.
- Realtime: server-clock SSE delta cursor; event-closed/opened drive the UI
  live; feed_delta rate-limited; like returns {liked, like_count} to fix
  multi-device drift; lightbox live comments; diashow delta backfill.
- Forgotten-PIN in-app request flow; simultaneous same-name join returns 409;
  quota increment is transactional; operator floor.

Adds e2e/specs/10-flow-review/ (offline resume, export integrity, deterministic
anti-race guard) and updates existing specs for the new contracts.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/src/main.rs

@@ -44,6 +44,18 @@ async fn main() -> Result<()> {
 
     let state = AppState::new(pool.clone(), config.clone());
 
+    // Re-spawn exports for events that were released but whose keepsake never finished
+    // (crash mid-export). Needs the media/export paths + SSE sender, so it runs here
+    // rather than inside `startup_recovery`. Fire-and-forget: the workers run in the
+    // background; the HTTP server can start accepting requests meanwhile.
+    services::export::recover_exports(
+        pool.clone(),
+        config.media_path.clone(),
+        config.export_path.clone(),
+        state.sse_tx.clone(),
+    )
+    .await;
+
     // Hourly background hygiene: prune expired sessions, evict cold rate-limiter
     // keys. Keeps the DB and process from growing unboundedly over multi-day events.
     services::maintenance::spawn_periodic_tasks(
@@ -60,8 +72,12 @@ async fn main() -> Result<()> {
         .route("/api/v1/event", get(handlers::public::get_public_event))
         .route("/api/v1/join", post(auth::handlers::join))
         .route("/api/v1/recover", post(auth::handlers::recover))
+        // Forgotten-PIN escape hatch: ask a host to reset it (unauthenticated, throttled).
+        .route("/api/v1/recover/request", post(auth::handlers::request_pin_reset))
         .route("/api/v1/admin/login", post(auth::handlers::admin_login))
         .route("/api/v1/session", delete(auth::handlers::logout))
+        // "Sign out everywhere" — revoke all of the caller's sessions.
+        .route("/api/v1/sessions", delete(auth::handlers::logout_all))
         // Upload — HTTP-level body cap as an OOM backstop. The handler still enforces
         // the precise per-class limits from DB config (max_image/video_size_mb); this
         // layer just stops a multi-GB body from being buffered into memory before that
@@ -118,6 +134,14 @@ async fn main() -> Result<()> {
             "/api/v1/host/users/{id}/pin-reset",
             post(handlers::host::reset_user_pin),
         )
+        .route(
+            "/api/v1/host/pin-reset-requests",
+            get(handlers::host::list_pin_reset_requests),
+        )
+        .route(
+            "/api/v1/host/pin-reset-requests/{id}",
+            delete(handlers::host::dismiss_pin_reset_request),
+        )
         .route("/api/v1/host/upload/{id}", delete(handlers::host::host_delete_upload))
         .route("/api/v1/host/comment/{id}", delete(handlers::host::host_delete_comment))
         // Export (all authenticated users)