Stop NZB job reuse from handing back an already not-wanted job hash

[zab1996]

Summary

Fixes cli_mount NZB reuse loops, junk/trailer collection, rescrape re-bind regressions, queue/mount drift, and adds repair UX plus a Junk Files audit for symlink-mode libraries.

Job reuse & blacklist

• Reuse paths check is_magnet_not_wanted() on the provider job hash (not just guid/segment ID or “job alive”).
• Terminal failures (ghost job, folder never appeared, health broken, ffprobe reject, supersede cancel) blacklist hash/guid/segment and reset item fields via shared blacklist_and_cleanup_nzb_failure().
• Supersede cancel deletes the prior in-flight job when Adding binds a new one; clears health-cache so orphans don’t accumulate.
• Movie reuse also blocks not-wanted hashes and jobs with known-unplayable files.
• Bulk rescrape fully clears blacklist state so items can try previously blocked releases again.
• Drop stale in-memory NZB queue entries when the mount folder is gone.

Size validation (individual movies/episodes only)

• Reject when downloaded video is <10% of advertised size — in Adding and again at symlink time.
• Pick largest episode-matching file when a folder has multiple videos (RAR splits); fix climount_sync assigning tiny splits to duplicate rows.
• Fall back to item.size when scrape_results are cleared (e.g. after rescrape). Fails open when size data is missing; season packs skipped.

Rescrape

• Clear stale bind fields (debrid_folder_name, scrape_results, nzb_segment_id, etc.) and sync in-memory queues immediately.
• Block all sibling season-pack reuse while rescrape_original_torrent_title is set; preserve that marker across intermediate NZB failures.
• Prevents rescrapped episodes from immediately re-binding the dead season pack that triggered the rescrape.

Repair — junk guard

• Detect junk sources (sample/trailer release tags, size mismatch, relative junk in pack) before NZB/debrid repair runs.
• Segment-based sample/trailer detection: flags standalone release tags (S01E01.trailer.1080p) but not title words (Punch Drunk Trailer Trashed, Trailer Park Boys).
• Shared logic in is_unwanted_file() for scrape filtering, repair guards, and Junk Files audit.
• Skip replacement scrape/submit; blacklist bad source; log skipped_junk_source in activity (Debrid Manager shows Junk outcome).
• Filter junk replacement candidates from scrape results so real broken files still repair normally.

Repair — in-flight panel (Debrid Manager)

• New In-Flight Repairs table on the Usenet tab for active nzb_playback_repairs rows (candidate search, pending verification, cleanup).
• Cancel stops the worker immediately (clears lease/backoff; activity → Cancelled).
• Send to Wanted cancels and resets the item for fresh scrape; tears down partial repair mounts (broken/candidate cli_mount jobs, symlinks, Plex entries) before re-scraping.

Junk Files audit (Debrid Manager)

• New Audit → Junk Files tab for symlink-mode libraries.
• Scans for undersized episodes/movies, sample/trailer tags, split-pack orphans, and NZB size mismatches.
• Splits likely junk (high confidence) from review-tier older/smaller releases.
• Fix resets Collected/Checking rows to Wanted, or deletes duplicate rows when a good Collected sibling already exists.
• Removes orphan junk files from the mount when no symlink depends on them.

Queue / mount alignment

• remove_nzb / remove_nzb_exact always call the queue delete endpoint after a successful browse delete, so queue.db stays aligned with entries.db.
• Applies during ffprobe reject, repair teardown, upgrades/supersedes, Junk Files Fix, and manual browse delete.
• INFO logging when companion queue rows are removed alongside storage delete.

Other

• Clear _nzb_confirmed_complete on broken-job rejection so Adding retries the next scrape result instead of advancing to Checking.
• Skip duplicate playback-repair candidate search when the item already collected elsewhere.
• Raise default Usenet retention days to 5000 for new installs (~13 years unless changed).

Test plan

• Stuck NZB (folder never appears) → blacklisted, fresh submission on retry (no reuse loop)
• Healthy in-flight job still reused when hash not blacklisted
• ~70–90 MiB download on ~4 GiB advertised release → rejected in Adding, blacklisted, next scrape tried
• Multi-file NZB folder → largest matching file symlinked; tiny splits rejected
• Rapid scrape cycling → superseded jobs deleted/blacklisted, no orphans
• ffprobe reject → hash in not-wanted, reuse skipped
• Junk source flagged broken → repair skipped, logged as Junk (no Wanted reset)
• In-flight playback repair → visible in Debrid Manager; Cancel / Send to Wanted stops retry loop
• Junk Files audit → flags undersized/split/mismatch junk; Fix resets to Wanted and removes mount/queue rows
• Bar Rescue S04E03 “Trailer Trashed” episode title → not flagged as junk after segment-based detection
• Rescrape → fresh scrape, no sibling pack re-bind, no “not found in checked location” loop
• pytest tests/test_nzb_size_validation.py tests/test_pick_best_video_file.py tests/test_nzb_supersede_cleanup.py tests/test_nzb_failure_cleanup.py tests/test_rescrape_pack_reuse.py tests/test_nzb_playback_repair.py tests/test_is_unwanted_file.py tests/test_climount_client_remove.py