feat: V13 — per-card "re-match this one file" (MNP 0.13)

A one-click alternative to the full "Fix match" search-and-pick flow, and
reachable without SSH (`meshbay-node video rematch` clears a whole group).

- MNP 0.13: tmdb_rematch / tmdb_rematch_ack (additive — an older node
  logs "unknown type", the button just does nothing). OP_TMDB_REMATCH,
  signed like tmdb_override (media_cache is shared node-wide).
- media_cache.drop_tmdb_match(file_id): forgets the match AND the
  override marker — deliberately stronger than clear_file_tmdb, since the
  operator is explicitly asking for a fresh resolution.
- webrtc_server: _do_tmdb_rematch / _admin_exec_tmdb_rematch, dispatch +
  admin-response routing, broadcasts tmdb_rematch_ack.
- transport.js: rematchTmdbMatch(fileId, signFn); 'tmdb_rematch' in the
  admin-op allowlist; tmdb_rematch_ack handled like tmdb_override_ack.
- video-app.js: a "Re-match" button beside "Fix match" in the detail
  modal (isNodeAdmin), then bumpMediaMetaGeneration(). video.rematch_one
  key in all ten locales.

docs/mediacenter.md §10.1: V8–V13 marked done.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018BMLQjqFGCize2KtNBT79v

20 files changed, 288 insertions, 5 deletions

diff --git a/packages/meshbay-common/src/meshbay_common/__init__.py b/packages/meshbay-common/src/meshbay_common/__init__.py
index d40f647..4612157 100644
--- a/packages/meshbay-common/src/meshbay_common/__init__.py
+++ b/packages/meshbay-common/src/meshbay_common/__init__.py
@@ -52,5 +52,9 @@ __version__ = "0.8.0"
 # 0.12: added `link_preview_req`/`link_preview_resp` — the node unfurls a URL
 # pasted in chat into an OpenGraph card. Additive: an older node logs "unknown
 # type" and the client just shows the bare link, as it always did.
-MNP_VERSION = "0.12"
+# 0.13: added `tmdb_rematch`/`tmdb_rematch_ack` — an operator dropping one
+# file's cached TMDB match so it re-resolves with the current matcher
+# (§10.1/V13). Additive: an older node logs "unknown type", the client's
+# button just does nothing.
+MNP_VERSION = "0.13"
 MHP_VERSION = "0.1"
diff --git a/packages/meshbay-common/src/meshbay_common/adminop.py b/packages/meshbay-common/src/meshbay_common/adminop.py
index f96dd57..762a2d1 100644
--- a/packages/meshbay-common/src/meshbay_common/adminop.py
+++ b/packages/meshbay-common/src/meshbay_common/adminop.py
@@ -83,6 +83,11 @@ OP_VIDEO_ROOT = "video_root"
 # (media_cache is shared, not per-viewer), so an unsigned override would let
 # any member vandalize another show's metadata.
 OP_TMDB_OVERRIDE = "tmdb_override"
+# "Re-match this one file" — drop its cached match (and any override marker)
+# so the next media_meta_req re-resolves with the current matcher. Signed for
+# the same reason as tmdb_override: media_cache is shared node-wide, so an
+# unsigned reset would let any member wipe another's correction.
+OP_TMDB_REMATCH = "tmdb_rematch"
 # MusicBrainz contact is now the owner's hub email (musicbrainz.py) — no
 # signed config op needed. Only the per-group toggle remains.
 # Whether the node calls MusicBrainz *at all* for this group — per-group from
diff --git a/packages/meshbay-common/src/meshbay_common/protocol.py b/packages/meshbay-common/src/meshbay_common/protocol.py
index 651fe2d..a3fb4de 100644
--- a/packages/meshbay-common/src/meshbay_common/protocol.py
+++ b/packages/meshbay-common/src/meshbay_common/protocol.py
@@ -109,6 +109,8 @@ class MNP:
     TMDB_SEARCH_RESP      = "tmdb_search_resp"       # node → client: candidate list (id, title, year, poster)
     TMDB_OVERRIDE         = "tmdb_override"          # operator → node: replace a show/movie's TMDB match
     TMDB_OVERRIDE_ACK     = "tmdb_override_ack"
+    TMDB_REMATCH          = "tmdb_rematch"           # operator → node: drop one file's match
+    TMDB_REMATCH_ACK      = "tmdb_rematch_ack"
     # Music app (docs/musicbay.md). Contact is derived from the owner's hub
     # email at login — no config/ack pair needed. Only the per-group toggle
     # remains.
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
index 55cf62e..c4ee388 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
@@ -186,6 +186,7 @@ export default {
   'video.source_file': 'Datei: {name}',
   'video.no_match': 'Keine sichere TMDB-Übereinstimmung — Dateiname wird angezeigt.',
   'video.versions': '{n} Versionen',
+  'video.rematch_one': 'Neu zuordnen',
 
   // Musik
   'music.mode_grid': 'Alben',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
index 4b9a4ee..16ae3ab 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
@@ -184,6 +184,7 @@ export default {
   'video.source_file': 'File: {name}',
   'video.no_match': 'No confident TMDB match — showing the filename.',
   'video.versions': '{n} versions',
+  'video.rematch_one': 'Re-match',
 
   // Music
   'music.mode_grid': 'Albums',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
index a65a619..88b222d 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
@@ -184,6 +184,7 @@ export default {
   'video.source_file': 'Archivo: {name}',
   'video.no_match': 'Sin coincidencia fiable en TMDB — se muestra el nombre del archivo.',
   'video.versions': '{n} versiones',
+  'video.rematch_one': 'Volver a asociar',
 
   // Música
   'music.mode_grid': 'Álbumes',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
index f026b3e..b08cf28 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
@@ -185,6 +185,7 @@ export default {
   'video.source_file': 'Fichier : {name}',
   'video.no_match': 'Aucune correspondance TMDB fiable — nom de fichier affiché.',
   'video.versions': '{n} versions',
+  'video.rematch_one': 'Relancer la recherche',
 
   // Musique
   'music.mode_grid': 'Albums',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
index 71ee6ab..f1e8467 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
@@ -185,6 +185,7 @@ export default {
   'video.source_file': 'File: {name}',
   'video.no_match': 'Nessuna corrispondenza TMDB affidabile — mostrato il nome del file.',
   'video.versions': '{n} versioni',
+  'video.rematch_one': 'Riassocia',
 
   // Musica
   'music.mode_grid': 'Album',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
index aa22837..95cc040 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
@@ -182,6 +182,7 @@ export default {
   'video.source_file': 'ファイル: {name}',
   'video.no_match': '確実なTMDB一致なし — ファイル名を表示しています。',
   'video.versions': '{n} 個のバージョン',
+  'video.rematch_one': '再マッチ',
 
   // 音楽
   'music.mode_grid': 'アルバム',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
index 9e5f8fb..076aa15 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
@@ -186,6 +186,7 @@ export default {
   'video.source_file': 'Bestand: {name}',
   'video.no_match': 'Geen betrouwbare TMDB-match — bestandsnaam wordt getoond.',
   'video.versions': '{n} versies',
+  'video.rematch_one': 'Opnieuw koppelen',
 
   // Muziek
   'music.mode_grid': 'Albums',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
index d8c4846..00ef59e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
@@ -193,6 +193,7 @@ export default {
   'video.source_file': 'Plik: {name}',
   'video.no_match': 'Brak pewnego dopasowania TMDB — pokazano nazwę pliku.',
   'video.versions': 'Wersje: {n}',
+  'video.rematch_one': 'Dopasuj ponownie',
 
   // Muzyka
   'music.mode_grid': 'Albumy',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
index 53390be..7d9173e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
@@ -186,6 +186,7 @@ export default {
   'video.source_file': 'Arquivo: {name}',
   'video.no_match': 'Sem correspondência confiável no TMDB — exibindo o nome do arquivo.',
   'video.versions': '{n} versões',
+  'video.rematch_one': 'Combinar de novo',
 
   // Música
   'music.mode_grid': 'Álbuns',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
index d845f6d..74d729e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
@@ -179,6 +179,7 @@ export default {
   'video.source_file': '文件：{name}',
   'video.no_match': '没有可靠的 TMDB 匹配 — 显示文件名。',
   'video.versions': '{n} 个版本',
+  'video.rematch_one': '重新匹配',
 
   // 音乐
   'music.mode_grid': '专辑',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/style.css b/packages/meshbay-hub/src/meshbay_hub/static/style.css
index a6934fc..8e714f3 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/style.css
+++ b/packages/meshbay-hub/src/meshbay_hub/static/style.css
@@ -2930,6 +2930,7 @@ h2 .gn-owner, h3 .gn-owner { font-size: 0.55em; }
 }
 .video-card-unmatched { outline: 1px dashed var(--warn, #d98324); outline-offset: -1px; }
 .video-version-list { margin-top: 12px; display: flex; flex-direction: column; gap: 4px; }
+.video-admin-actions { display: flex; gap: 8px; flex-wrap: wrap; margin: 8px 0; }
 .video-card-flag {
   display: inline-block;
   margin-left: 4px;
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index d6a28d9..5a6e36b 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -73,7 +73,7 @@ function _aborted() {
 // list is what lets a response two steps later be tied back to the right
 // one.
 const ADMIN_OP_TYPES = new Set([
-  'tmdb_override', 'tmdb_config', 'tmdb_enabled', 'video_root', 'audio_root',
+  'tmdb_override', 'tmdb_rematch', 'tmdb_config', 'tmdb_enabled', 'video_root', 'audio_root',
   'photo_roots',
   'musicbrainz_enabled', 'file_delete', 'dir_delete',
   'member_upload', 'apps_enabled', 'set_scan_settings', 'member_revoke',
@@ -916,6 +916,22 @@ class MeshBayTransport {
   }
 
   /**
+   * Drop one file's cached TMDB match so it re-resolves with the node's
+   * current matcher (§10.1/V13) — the one-click alternative to the full
+   * search-and-pick flow. Signed for the same reason as overrideTmdbMatch.
+   */
+  async rematchTmdbMatch(fileId, signFn) {
+    const msg = await this._sendAndWait({
+      type: 'tmdb_rematch', v: '0.7', file_id: fileId,
+    });
+    if (msg.type === 'error') throw new Error(msg.detail);
+    if (msg.type === 'admin_challenge') {
+      return this._authorizeAdminOp(msg, 'tmdb_rematch', `file_id=${fileId}`, signFn);
+    }
+    return msg;
+  }
+
+  /**
    * Set/clear a custom TMDB API token, and/or set the language TMDB is
    * queried in (e.g. "fr-FR") — one for the whole node, since both are one
    * operator's shared credential/cache, not a per-group concern (see
@@ -2032,6 +2048,11 @@ class MeshBayTransport {
         fileId: msg.file_id || '', tmdbId: msg.tmdb_id || '', mediaType: msg.media_type || '',
       });
     }
+    // Same shape: the operator dropped one file's match to have it
+    // re-resolved (§10.1/V13). No tmdbId — the node re-derives it.
+    if (msg.type === 'tmdb_rematch_ack' && this._onTmdbOverride) {
+      this._onTmdbOverride({ fileId: msg.file_id || '', tmdbId: '', mediaType: '' });
+    }
 
     // Same shape: the operator changed which folder is the Videos app's
     // entry point for this group.
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/video-app.js b/packages/meshbay-hub/src/meshbay_hub/static/video-app.js
index 48709f9..6d13e27 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/video-app.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/video-app.js
@@ -482,8 +482,22 @@ function VideoDetailModal({
 }) {
   const confident = Boolean(meta && meta.confidence && meta.tmdb_id);
   const [searching, setSearching] = useState(false);
+  const [rematching, setRematching] = useState(false);
   const mediaType = show ? 'tv' : 'movie';
 
+  // §10.1/V13: drop this file's cached match on the node and let it
+  // re-resolve with the current matcher — the one-click alternative to the
+  // full search-and-pick flow above.
+  const doRematch = useCallback(async () => {
+    if (rematching) return;
+    setRematching(true);
+    try {
+      await transportRef.current.rematchTmdbMatch(repEntry.id, buildSignFn(transportRef));
+      bumpMediaMetaGeneration();
+    } catch { /* leave the current match in place */ }
+    setRematching(false);
+  }, [rematching, repEntry, transportRef]);
+
   // Reset whenever a different file/show is opened in this same modal
   // instance — repEntry/show change identity, selectedSeason must not
   // silently keep pointing at whatever the previous show's season 4 was.
@@ -535,9 +549,14 @@ function VideoDetailModal({
             `}
           `}
           ${isNodeAdmin && html`
-            <button class="admin-btn video-fix-match" onClick=${() => setSearching(true)}>
-              ${t('video.fix_match')}
-            </button>
+            <div class="video-admin-actions">
+              <button class="admin-btn video-fix-match" onClick=${() => setSearching(true)}>
+                ${t('video.fix_match')}
+              </button>
+              <button class="admin-btn" onClick=${doRematch} disabled=${rematching}>
+                ${rematching ? html`<span class="spinner"></span>` : t('video.rematch_one')}
+              </button>
+            </div>
           `}
           ${showMultiSeason && html`
             <${SeasonTabs} seasons=${show.seasons} selected=${selectedSeason}
diff --git a/packages/meshbay-node/src/meshbay_node/media_cache.py b/packages/meshbay-node/src/meshbay_node/media_cache.py
index 4600a09..8233270 100644
--- a/packages/meshbay-node/src/meshbay_node/media_cache.py
+++ b/packages/meshbay-node/src/meshbay_node/media_cache.py
@@ -175,6 +175,18 @@ class MediaCache:
             "(SELECT file_id FROM tmdb_override)", (file_id,))
         await self._db.commit()
 
+    async def drop_tmdb_match(self, file_id: str) -> None:
+        """
+        Full per-file reset: forget the match *and* any manual override
+        marker, so the next `media_meta_req` re-resolves from scratch with
+        the current matcher. This is the explicit operator "re-match this
+        one" action (§10.1/V13) — deliberately stronger than
+        `clear_file_tmdb`, which spares an override.
+        """
+        await self._db.execute("DELETE FROM file_tmdb WHERE file_id = ?", (file_id,))
+        await self._db.execute("DELETE FROM tmdb_override WHERE file_id = ?", (file_id,))
+        await self._db.commit()
+
     async def clear_tmdb_matches(self, file_ids: list[str]) -> int:
         """
         Drop the auto-resolved file->tmdb mappings for these files so the
diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
index c75819e..af6bf08 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
@@ -70,6 +70,7 @@ from meshbay_common.adminop import (
     OP_TMDB_ENABLED,
     OP_VIDEO_ROOT,
     OP_TMDB_OVERRIDE,
+    OP_TMDB_REMATCH,
     OP_MUSICBRAINZ_ENABLED,
     OP_AUDIO_ROOT,
     OP_PHOTO_ROOTS,
@@ -475,6 +476,8 @@ class WebRTCPeerSession:
                 self._spawn(self._do_tmdb_search_request(msg))
             elif mtype == MNP.TMDB_OVERRIDE:
                 self._do_tmdb_override(msg)
+            elif mtype == MNP.TMDB_REMATCH:
+                self._do_tmdb_rematch(msg)
             elif mtype == MNP.MUSICBRAINZ_ENABLED:
                 self._do_musicbrainz_enabled(msg)
             elif mtype == MNP.MUSIC_META_REQ:
@@ -3171,6 +3174,49 @@ class WebRTCPeerSession:
             except Exception:
                 pass
 
+    def _do_tmdb_rematch(self, msg: dict) -> None:
+        """
+        An operator dropping one file's cached TMDB match so it re-resolves
+        with the current matcher (§10.1/V13) — the one-click alternative to
+        the full search-and-pick "Fix match" flow, and reachable without
+        SSH (`meshbay-node video rematch` clears a whole group). Signed like
+        `tmdb_override`: `media_cache` is shared node-wide.
+        """
+        file_id = msg.get("file_id")
+        if not isinstance(file_id, str) or not file_id:
+            self._send({"type": "error", "detail": "Missing file_id"})
+            return
+        if not self._group_ctx()["index"].get_entry(file_id):
+            self._send({"type": "error", "detail": "File not found"})
+            return
+        if not self._has_admin_authority():
+            self._send({"type": "error", "detail": "No authorized key for this"})
+            return
+        self._issue_admin_challenge(OP_TMDB_REMATCH, f"file_id={file_id}")
+
+    async def _admin_exec_tmdb_rematch(
+        self, pending: dict, transcript: bytes, sig: bytes,
+    ) -> None:
+        subject = pending["subject"]
+        if not await self._verify_admin_sig(transcript, sig):
+            self._send({"type": "error", "detail": "Signature verification failed"})
+            self._audit("admin_auth_failed", f"tmdb_rematch:{subject}")
+            return
+        file_id = dict(part.split("=", 1) for part in subject.split(","))["file_id"]
+        media_cache = self._ctx.get("media_cache")
+        if media_cache is None:
+            self._send({"type": "error", "detail": "Media cache not available"})
+            return
+        await media_cache.drop_tmdb_match(file_id)
+        self._audit("tmdb_rematch", subject)
+
+        notice = {"type": MNP.TMDB_REMATCH_ACK, "v": MNP_VERSION, "file_id": file_id}
+        for uid, session in list(self._peer_registry().items()):
+            try:
+                session._send(notice)
+            except Exception:
+                pass
+
     async def _tmdb_search(self, tmdb_client, entry, is_show: bool):
         """
         §3.3's retry ladder — same shape for movies and shows (§10.1/V8).
@@ -3874,6 +3920,9 @@ class WebRTCPeerSession:
         elif pending["op"] == OP_TMDB_OVERRIDE:
             self._spawn(
                 self._admin_exec_tmdb_override(pending, transcript, sig_bytes))
+        elif pending["op"] == OP_TMDB_REMATCH:
+            self._spawn(
+                self._admin_exec_tmdb_rematch(pending, transcript, sig_bytes))
         elif pending["op"] == OP_MUSICBRAINZ_ENABLED:
             self._spawn(
                 self._admin_exec_musicbrainz_enabled(pending, transcript, sig_bytes))
diff --git a/packages/meshbay-node/tests/test_media_cache.py b/packages/meshbay-node/tests/test_media_cache.py
index 4e65b24..f12a366 100644
--- a/packages/meshbay-node/tests/test_media_cache.py
+++ b/packages/meshbay-node/tests/test_media_cache.py
@@ -107,6 +107,19 @@ async def test_clear_file_tmdb_drops_one_auto_match_but_keeps_an_override(cache)
 
 
 @pytest.mark.asyncio
+async def test_drop_tmdb_match_forgets_both_the_match_and_the_override(cache):
+    await cache.set_file_tmdb("f", "10", "movie")
+    await cache.mark_tmdb_override("f")
+
+    await cache.drop_tmdb_match("f")
+
+    assert await cache.get_file_tmdb("f") is None
+    # override marker is gone: a fresh match is now treated as ordinary
+    await cache.set_file_tmdb("f", "20", "movie")
+    assert await cache.clear_tmdb_matches(["f"]) == 1
+
+
+@pytest.mark.asyncio
 async def test_prune_file_also_clears_the_override_marker(cache):
     await cache.set_file_tmdb("gone", "10", "movie")
     await cache.mark_tmdb_override("gone")
diff --git a/packages/meshbay-node/tests/test_tmdb_rematch_policy.py b/packages/meshbay-node/tests/test_tmdb_rematch_policy.py
new file mode 100644
index 0000000..ff259c1
--- /dev/null
+++ b/packages/meshbay-node/tests/test_tmdb_rematch_policy.py
@@ -0,0 +1,147 @@
+"""
+`tmdb_rematch` (§10.1/V13) — an operator dropping one file's cached TMDB
+match so it re-resolves with the current matcher. Signed like
+`tmdb_override` (media_cache is shared node-wide); unlike `clear_file_tmdb`
+it forgets a manual override marker too, since the operator is explicitly
+asking for a fresh resolution.
+"""
+
+import hashlib
+
+import pytest
+from conftest import one_root
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
+from meshbay_common.adminop import OP_TMDB_REMATCH
+from meshbay_common.protocol import MNP, IndexEntry
+from meshbay_node.indexer.group_index import GroupIndex
+from meshbay_node.media_cache import MediaCache
+from meshbay_node.transport.webrtc_server import WebRTCPeerSession
+
+pytestmark = pytest.mark.asyncio
+
+
+def _session(tmp_path, user_id, *, operator=None):
+    shared = tmp_path / "shared"
+    shared.mkdir(exist_ok=True)
+    index = GroupIndex(group_id="g" * 32, sk_node=Ed25519PrivateKey.generate())
+    s = WebRTCPeerSession.__new__(WebRTCPeerSession)
+    s._ctx = {"roots": one_root(shared), "index": index, "sk_node": index.sk_node,
+              "node_user_id": operator}
+    s._group_id = None
+    s._user_id = user_id
+    s._pk_user = ""
+    s.sent = []
+    s._send = s.sent.append
+    s._audit = lambda *a, **k: None
+    return s
+
+
+def _entry(name):
+    digest = hashlib.sha256(name.encode()).hexdigest()
+    return IndexEntry(id=digest, name=name, path="movies", size=1, type="video",
+                      added_at=0, display_title="Some Film")
+
+
+async def _true():
+    return True
+
+
+async def test_missing_file_id_is_refused(tmp_path):
+    s = _session(tmp_path, "op", operator="op")
+    s._has_admin_authority = lambda: True
+    issued = []
+    s._issue_admin_challenge = lambda op, subject: issued.append((op, subject))
+
+    s._do_tmdb_rematch({})
+
+    assert not issued
+    assert [m for m in s.sent if m.get("type") == "error"]
+
+
+async def test_unknown_file_id_is_refused(tmp_path):
+    s = _session(tmp_path, "op", operator="op")
+    s._has_admin_authority = lambda: True
+    issued = []
+    s._issue_admin_challenge = lambda op, subject: issued.append((op, subject))
+
+    s._do_tmdb_rematch({"file_id": "nope"})
+
+    assert not issued
+    assert [m for m in s.sent if m.get("type") == "error"]
+
+
+async def test_no_authorized_key_is_refused(tmp_path):
+    s = _session(tmp_path, "member", operator="the-operator")
+    e = _entry("some.film.2001.mkv")
+    s._ctx["index"].add_entry(e)
+    s._has_admin_authority = lambda: False
+
+    s._do_tmdb_rematch({"file_id": e.id})
+
+    assert [m for m in s.sent if m.get("type") == "error"]
+
+
+async def test_a_valid_request_is_signed(tmp_path):
+    s = _session(tmp_path, "op", operator="op")
+    e = _entry("some.film.2001.mkv")
+    s._ctx["index"].add_entry(e)
+    s._has_admin_authority = lambda: True
+    issued = []
+    s._issue_admin_challenge = lambda op, subject: issued.append((op, subject))
+
+    s._do_tmdb_rematch({"file_id": e.id})
+
+    assert issued == [(OP_TMDB_REMATCH, f"file_id={e.id}")]
+
+
+async def test_exec_drops_the_match_and_the_override_marker(tmp_path):
+    s = _session(tmp_path, "op", operator="op")
+    e = _entry("some.film.2001.mkv")
+    s._ctx["index"].add_entry(e)
+
+    media_cache = MediaCache(db_path=tmp_path / "media_cache.db")
+    await media_cache.open()
+    try:
+        s._ctx["media_cache"] = media_cache
+        await media_cache.set_file_tmdb(e.id, "wrong-id", "movie")
+        await media_cache.mark_tmdb_override(e.id)
+        s._verify_admin_sig = lambda transcript, sig: _true()
+        peer = type("Peer", (), {"sent": []})()
+        peer._send = peer.sent.append
+        s._peer_registry = lambda: {"peer-1": peer}
+
+        await s._admin_exec_tmdb_rematch(
+            {"subject": f"file_id={e.id}"}, b"transcript", b"sig")
+
+        assert await media_cache.get_file_tmdb(e.id) is None
+        # the override marker is gone too, so a later group-wide rematch
+        # would treat a fresh match as ordinary
+        await media_cache.set_file_tmdb(e.id, "fresh", "movie")
+        assert await media_cache.clear_tmdb_matches([e.id]) == 1
+        assert [m for m in peer.sent if m.get("type") == MNP.TMDB_REMATCH_ACK]
+    finally:
+        await media_cache.close()
+
+
+async def test_exec_refuses_a_bad_signature(tmp_path):
+    s = _session(tmp_path, "op", operator="op")
+    e = _entry("some.film.2001.mkv")
+    s._ctx["index"].add_entry(e)
+
+    media_cache = MediaCache(db_path=tmp_path / "media_cache.db")
+    await media_cache.open()
+    try:
+        s._ctx["media_cache"] = media_cache
+        await media_cache.set_file_tmdb(e.id, "keep-me", "movie")
+
+        async def _false():
+            return False
+        s._verify_admin_sig = lambda transcript, sig: _false()
+
+        await s._admin_exec_tmdb_rematch(
+            {"subject": f"file_id={e.id}"}, b"transcript", b"badsig")
+
+        assert await media_cache.get_file_tmdb(e.id) == ("keep-me", "movie")
+        assert [m for m in s.sent if m.get("type") == "error"]
+    finally:
+        await media_cache.close()