fix(crawler): reap dead jobs alongside done ones

The retention reaper deleted only `state = 'done'` rows, so terminal
`dead` jobs (retries exhausted) accumulated in crawler_jobs forever —
slow unbounded table growth. Both states are end-of-life and never
leased again.

Rename `reap_done` → `reap_terminal` and broaden the filter to
`state IN ('done','dead')`; `pending`/`running` stay untouched. Test
extended to assert old done + old dead both reap while fresh terminal and
old-but-active rows survive.

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

backend/src/crawler/daemon.rs

@@ -301,9 +301,9 @@ impl CronContext {
                 }
                 Err(e) => tracing::error!(?e, "cron: enqueue_bookmarked_pending failed"),
             }
-            match jobs::reap_done(pool, retention_days).await {
-                Ok(n) => tracing::info!(reaped = n, "cron: done-job reaper finished"),
-                Err(e) => tracing::error!(?e, "cron: done-job reaper failed"),
+            match jobs::reap_terminal(pool, retention_days).await {
+                Ok(n) => tracing::info!(reaped = n, "cron: terminal-job reaper finished"),
+                Err(e) => tracing::error!(?e, "cron: terminal-job reaper failed"),
             }
             match crate::repo::crawl_metrics::reap(pool, metrics_retention_days).await {
                 Ok(n) => tracing::info!(reaped = n, "cron: crawl-metrics reaper finished"),

backend/src/crawler/jobs.rs

@@ -485,16 +485,19 @@ pub async fn reclaim_orphaned(pool: &PgPool) -> sqlx::Result<u64> {
     Ok(result.rows_affected())
 }
 
-/// Delete `done` jobs whose `updated_at` is older than `retention_days`
-/// days. `0` disables the reaper without touching the table. Returns the
-/// number of rows removed.
-pub async fn reap_done(pool: &PgPool, retention_days: u32) -> sqlx::Result<u64> {
+/// Delete **terminal** jobs (`done` or `dead`) whose `updated_at` is older
+/// than `retention_days` days. Both states are end-of-life — `done`
+/// succeeded, `dead` exhausted its retries — and neither is ever leased
+/// again, so reaping only `done` left `dead` rows to accumulate forever.
+/// `pending` / `running` are active and never touched. `0` disables the
+/// reaper without touching the table. Returns the number of rows removed.
+pub async fn reap_terminal(pool: &PgPool, retention_days: u32) -> sqlx::Result<u64> {
     if retention_days == 0 {
         return Ok(0);
     }
     let result = sqlx::query(
         "DELETE FROM crawler_jobs \
-          WHERE state = 'done' \
+          WHERE state IN ('done', 'dead') \
             AND updated_at < now() - ($1::bigint || ' days')::interval",
     )
     .bind(retention_days as i64)

backend/src/repo/crawl_metrics.rs

@@ -187,7 +187,7 @@ pub async fn list_ops(
 }
 
 /// Delete metric rows older than `retention_days`. `0` disables the reaper
-/// (returns 0 without touching the table). Mirrors `jobs::reap_done`.
+/// (returns 0 without touching the table). Mirrors `jobs::reap_terminal`.
 pub async fn reap(pool: &PgPool, retention_days: u32) -> sqlx::Result<u64> {
     if retention_days == 0 {
         return Ok(0);

backend/src/repo/crawler.rs

@@ -903,9 +903,8 @@ pub struct JobHistoryFilter<'a> {
 /// manga/chapter/page context (best-effort) so the table can label rows.
 /// Returns the page slice plus the filtered total for pagination.
 ///
-/// History depth is bounded by the done-job reaper (`reap_done`): completed
-/// jobs older than the retention window are gone. Terminal `dead` jobs
-/// persist until requeued.
+/// History depth is bounded by the terminal-job reaper (`reap_terminal`):
+/// `done` and `dead` jobs older than the retention window are gone.
 pub async fn list_job_history(
     pool: &PgPool,
     filter: JobHistoryFilter<'_>,