Discovery final review fixes: lean publish, robust scoring, cheap prune (BL-0051)

- Cache prune counts directory entries first and only reads files when over
  the cap; tests for cross-kind prune, schema-mismatch and corrupt entries.
- Scoring tolerates malformed manga.json and cached records (non-list tags,
  object or null relations, non-object items); a tag without a rank no longer
  passes the top-tag filter; authors without an integer AniList id are dropped.
- discovery.json publishes only candidates some feed shows; examined/clipped
  still describe the pool. Tests that asserted the published count equals the
  pool size now check the pool via candidatePool() and the published set
  against the feeds.
- The post-harvest rescore failure test now breaks discovery.json right before
  the publish (via a scraper stand-in) instead of relying on tags: 5, and a
  following successful harvest clears the stale lastError.
- Consent text names everything sent to AniList; paused label mentions admin
  harvests; the UI test asserts the XSS seed instead of skipping it.
- Slot-mix test proves the fresh/outside reservations matter.
- Docs: privacy note, fresh fallback reason, per-period cap, dry-run wording,
  published-candidate rule; plan/spec hygiene and spec status.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

discovery/cli.js

@@ -22,7 +22,8 @@ const greatest = loadCatalog(arg('--catalog', path.join(__dirname, '..', 'greate
 const harvestDir = path.join(data, 'discovery-cache');
 const harvestCache = fs.existsSync(harvestDir) ? new DiscoveryCache(harvestDir) : null;
 const result = generate({ db, library, greatest, cacheDir: path.join(data, 'scraper', 'metadata', 'anilist'), harvestCache });
-const summary = { examined: result.examined, candidates: Object.keys(result.candidates).length,
+// candidates: the ones some feed shows (what a run would publish); examined/clipped: the whole pool.
+const summary = { examined: result.examined, clipped: result.clipped, candidates: Object.keys(result.candidates).length,
   optedInUsers: Object.values(db.users || {}).filter(u => u.settings?.discoveryEnabled).length,
   feedSizes: Object.values(result.feeds).filter(f => !f.disabled).map(f => f.items.length) };
 if (process.argv.includes('--show')) summary.titles = Object.values(result.feeds).find(f => !f.disabled)?.items