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>

test/discovery-cache.test.js

@@ -49,6 +49,48 @@ test('prune keeps the newest maxFiles', (t) => {
   assert.notEqual(cache.get('title', 5), null);
 });
 
+test('prune removes the oldest entries across kinds', (t) => {
+  const { clock, cache } = setup(t, { maxFiles: 3 });
+  const kinds = ['title', 'recs', 'creator', 'fresh', 'tagTop'];
+  kinds.forEach((kind, i) => { clock.t += 1000; cache.put(kind, i, { i }); });
+  assert.equal(cache.stats().files, 3);
+  assert.equal(cache.get('title', 0), null);
+  assert.equal(cache.get('recs', 1), null);
+  for (const [i, kind] of kinds.entries()) if (i >= 2) assert.notEqual(cache.get(kind, i), null, kind);
+});
+
+test('a write under the cap does not read other entries', (t) => {
+  const { dir, cache } = setup(t, { maxFiles: 10 });
+  cache.put('recs', 7, {});
+  const file = path.join(dir, 'recs', fs.readdirSync(path.join(dir, 'recs'))[0]);
+  fs.writeFileSync(file, '{broken');
+  cache.put('title', 1, {});
+  assert.equal(fs.readFileSync(file, 'utf8'), '{broken');
+});
+
+test('over the cap, corrupt and schema-mismatch entries go before valid ones', (t) => {
+  const { dir, clock, cache } = setup(t, { maxFiles: 2 });
+  cache.put('recs', 1, {});
+  cache.put('recs', 2, {});
+  const [first, second] = fs.readdirSync(path.join(dir, 'recs')).map(name => path.join(dir, 'recs', name));
+  fs.writeFileSync(first, '{broken');
+  fs.writeFileSync(second, JSON.stringify({ schema: 2, kind: 'recs', key: 2, fetchedAt: new Date(clock.t).toISOString(), data: {} }));
+  clock.t += 1000;
+  cache.put('title', 3, {});
+  assert.equal(fs.existsSync(first), false);
+  assert.equal(fs.existsSync(second), false);
+  assert.notEqual(cache.get('title', 3), null);
+});
+
+test('schema-mismatch entry is deleted like a corrupt one', (t) => {
+  const { dir, clock, cache } = setup(t);
+  cache.put('recs', 7, {});
+  const file = path.join(dir, 'recs', fs.readdirSync(path.join(dir, 'recs'))[0]);
+  fs.writeFileSync(file, JSON.stringify({ schema: 2, kind: 'recs', key: 7, fetchedAt: new Date(clock.t).toISOString(), data: {} }));
+  assert.equal(cache.get('recs', 7), null);
+  assert.equal(fs.existsSync(file), false);
+});
+
 test('corrupt entry is deleted', (t) => {
   const { dir, cache } = setup(t);
   cache.put('recs', 7, {});