fix(hub): one entry per file in the Search view's Videos grid

A library shared by two groups arrived in the cross-group Search view as
two entries per file: every film was two poster cards, every episode was
listed twice in the season list under the synopsis. Inside one group
this cannot happen — GroupIndex is keyed by blake3 — so the duplication
was the Search page's own, from concatenating N independently keyed
indexes.

source-merge.js folds entries on the content hash and resolves one
source per *unit* (a film, a whole show), so a season does not scatter
across two nodes. A group hosted by the reader's own node wins; failing
that the pick is a hash of the unit key and the reader's id, stable
across renders and reloads — a source that changed mid-stream would tear
down the connection under a film that is playing — and spread across
readers and units.

The units come from video-app.js's own groupVideoEntries rather than a
second copy of its keys here. Only the Videos view is wired up so far;
Music, Photos, failover and the "N sources" badge are phases 5-8 of
docs/refactoring-search.md.

Every test was checked against the fix removed. That is how the first
version of "a unit's files share its source" turned out to prove
nothing: with every episode in every group, per-file and per-unit
picking give the same answer, so it passed against a per-file
implementation. It now uses a unit whose files have unequal sources.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AbwJDbNTkiRUh7HTWEoyss

1 files changed, 51 insertions, 5 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/search-page.js b/packages/meshbay-hub/src/meshbay_hub/static/search-page.js
index ec92e76..5897acb 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/search-page.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/search-page.js
@@ -8,11 +8,12 @@ import {
   HUB, session, cacheGroupIndex, hubFetch, ensureFreshToken, _loadBundleKey,
 } from './hub-client.js';
 import { FilesPanel, FilePreview } from './files-app.js';
-import { VideoApp } from './video-app.js';
+import { VideoApp, groupVideoEntries } from './video-app.js';
 import { MusicApp } from './music-app.js';
 import { PhotosApp } from './photos-app.js';
 import { VideoPlayer } from './video-player.js';
 import { transfers } from './transfers.js';
+import { mergeUnitEntries } from './source-merge.js';
 
 const BATCH_SIZE = 3;
 // One WebRTC peer connection per group the search view touches. The cap bounds
@@ -151,7 +152,13 @@ async function fetchGroupIndex(groupId, token, bundleKey, username, userId) {
       audioRoot: ack.audio_root || '',
       photoRoots: ack.photo_roots || [],
     };
-    return { entries: indexMsg.entries || [], roots };
+    // Which of the reader's groups sit on their own node — the tie-breaker
+    // when the same file is announced by several of them
+    // (docs/refactoring-search.md §5.3). Computed by the node from its own
+    // record of who it belongs to (webrtc_server.py's _is_node_admin), never
+    // from a hub claim, and deliberately not written to the index cache: it
+    // describes this connection, not the group's content.
+    return { entries: indexMsg.entries || [], roots, isNodeAdmin: !!ack.is_node_admin };
   } finally {
     try { transport.close(); } catch {}
   }
@@ -200,6 +207,32 @@ function underRoot(entry, root) {
   return p === root || p.startsWith(root + '/');
 }
 
+// -- Merging the same file announced by several groups ------------------------
+//
+// A directory shared by two groups — the reason two groups exist at all:
+// different people invited to different libraries — arrived here as two
+// entries per file, so a film showed as two poster cards and every episode
+// twice inside a show. `source-merge.js` folds them on the content hash and
+// resolves one source per *unit*. See docs/refactoring-search.md.
+//
+// The units come from video-app.js's own `groupVideoEntries`, never from a
+// second copy of its keys here: a copy would keep agreeing with the original
+// right up until one of them changed, and the symptom would be a show whose
+// episodes stream from two different nodes. Running it twice per recompute (it
+// runs again inside VideoApp) is a linear pass over an index already in memory
+// and already re-walked on every keystroke of the filter.
+//
+// One naive unit per copy of a film rather than a pre-grouped one:
+// `mergeUnitEntries` folds lists that share a key, so the two copies become
+// one unit without this having to group them first.
+function videoUnits(entries) {
+  const { movies, shows } = groupVideoEntries(entries, SEARCH_VIDEO_ROOT);
+  return [
+    ...movies.map((e) => ({ key: `movie:${e.id}`, entries: [e] })),
+    ...shows.map((s) => ({ key: `show:${s.title}`, entries: s.episodes })),
+  ];
+}
+
 function SearchPage({ token, username, userId, groups, onPlayQueue, userPrefs }) {
   const [indexedGroups, setIndexedGroups] = useState(new Map());
   const [progress, setProgress] = useState({ done: 0, total: 0, unreachable: [] });
@@ -388,7 +421,20 @@ function SearchPage({ token, username, userId, groups, onPlayQueue, userPrefs })
     return dirs;
   }, [indexedGroups]);
 
-  // Videos view: pre-filtered by videoRoot, path-prefixed
+  // How a unit's source is chosen, shared by every merged view
+  // (docs/refactoring-search.md §5.3). `isLocal` reads the flag the node itself
+  // put in the handshake ack — computed from its own record of who it belongs
+  // to (webrtc_server.py's `_is_node_admin`), never from a hub claim.
+  const mergeOpts = useMemo(() => ({
+    salt: userId || '',
+    isLocal: (gid) => {
+      const data = indexedGroups.get(gid);
+      return !!(data && data.isNodeAdmin);
+    },
+  }), [indexedGroups, userId]);
+
+  // Videos view: pre-filtered by videoRoot, path-prefixed, then merged so a
+  // file several groups share is one card and one list entry.
   const videoEntries = useMemo(() => {
     const result = [];
     for (const [groupId, data] of indexedGroups) {
@@ -411,8 +457,8 @@ function SearchPage({ token, username, userId, groups, onPlayQueue, userPrefs })
         });
       }
     }
-    return result;
-  }, [indexedGroups, q, matchesQuery, connectionGen]);
+    return mergeUnitEntries(videoUnits(result), mergeOpts);
+  }, [indexedGroups, q, matchesQuery, connectionGen, mergeOpts]);
 
   // Music view: pre-filtered by audioRoot, path-prefixed
   const musicEntries = useMemo(() => {