Fix stuck dedup candidate, enrich timeout/starvation, and qobuz status error

1. enrich-buy-url.py re-queried every no-match track on every daily run (external,
   rate-limited lookups over the whole backlog), which blew past its 30-min
   timeout. Cache "tried, no match" with a BUY_URL_TRIED marker tag and skip
   those for 30 days (--force still re-checks). This is what made "Look up buy
   links" fail with TIMEOUT after 1800s.

2. Move maintenance:enrich_buy_url to run last (09:45) in the 9am block, after
   the fingerprint index (09:25) and status report (09:30). enrich starting at
   09:10 and holding the shared lock is what left "Rebuild fingerprint index"
   skipped_lock.

3. pipeline-status.sh: guard the qobuz/app_id read with a file-exists check.
   `< missing 2>/dev/null` still leaks the shell's redirection error (opened
   before 2>/dev/null applies), so the daily report logged
   "qobuz/app_id: No such file or directory" every run.

4. dedup confirm_and_apply: a candidate whose delete target no longer exists
   (already removed by an earlier dedup/upgrade/hand) was filtered out and the
   apply silently no-op'd, leaving it stuck in the queue with no way to delete
   or clear it (the 100 gecs case). Now mark such candidates applied so a Delete
   click clears them. Covered by tests/test_dedup_review.py.

Tests: 46 green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pipeline/lib/enrich-buy-url.py

@@ -40,6 +40,18 @@ from pathlib import Path
 
 UA = "Mozilla/5.0 (X11; Linux x86_64) enrich-buy-url/1.0"
 BUY_URL_TAG = "COMMERCIAL_INFORMATION"
+# Marker (unix timestamp) stamped on a FLAC when a buy-link lookup found
+# nothing, so daily runs don't re-query the whole no-match backlog every time.
+# Retried after the window below; --force ignores it.
+BUY_URL_TRIED_TAG = "BUY_URL_TRIED"
+_TRIED_RETRY_DAYS = 30
+
+
+def _tried_recently(ts_str):
+    try:
+        return (time.time() - float(ts_str)) < _TRIED_RETRY_DAYS * 86400
+    except (TypeError, ValueError):
+        return False
 ITUNES_SEARCH = "https://itunes.apple.com/search"
 BC_AUTOCOMPLETE = "https://bandcamp.com/api/bcsearch_public_api/1/autocomplete_elastic"
 QOBUZ_SEARCH = "https://www.qobuz.com/api.json/0.2/track/search"
@@ -451,6 +463,14 @@ def main():
             else:
                 continue                      # already tagged, not up for upgrade
         else:
+            # Skip tracks we recently tried and found nothing for, so a daily
+            # run doesn't re-query the whole no-match backlog (external, rate-
+            # limited lookups) every time -- that churn is what pushed this job
+            # past its timeout. --force re-checks everything.
+            if not args.force:
+                tried = flac_tag(sp, BUY_URL_TRIED_TAG)
+                if tried and _tried_recently(tried):
+                    continue
             run_sources = cascade             # untagged, or --force
         artist = flac_tag(sp, "ARTIST").split(";")[0].strip() or flac_tag(sp, "ALBUMARTIST")
         title = flac_tag(sp, "TITLE")
@@ -470,6 +490,10 @@ def main():
 
         rel = sp[len(args.library):].lstrip("/")
         if not url:
+            # Record that we checked and found nothing, so the next daily run
+            # skips it (until the retry window). Apply mode only.
+            if args.apply:
+                set_flac_tag(sp, BUY_URL_TRIED_TAG, str(int(time.time())))
             continue
         found += 1
         by_source[src] += 1