feat(node,hub): add Videos group app (poster grid, flat list, TMDB metadata)

Implements docs/mediacenter.md: a "Videos" group application built on the
existing files index rather than a separate catalogue. On the node side,
new indexer enrichment (technical probe, filename/season parsing, thumbnail
generation) runs per-file once an operator has chosen a video_root for the
group, plus a TMDB client for on-demand poster/metadata lookups (never
client-side, thumbnails delivered over the existing chunk path). On the hub
side, a new video-app.js renders a lazily-mounted poster grid or a
thumbnail-only flat list, with TMDB entirely optional per group.

Along the way: the global apps registry now drives Settings' default-tab
picker instead of a hardcoded list, and the video_root is configured from
group Settings (like uploads) rather than from Files, with the node
refusing to run any TMDB/thumbnail work until one is set.

Fixes several bugs found via live testing against a real library, notably
a race between two effects writing the same "image ready" state that could
leave a poster grid spinning forever on a same-tab revisit — see
mediacenter.md §5.4 for the full account of each one.

1 files changed, 62 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ops.py b/packages/meshbay-node/src/meshbay_node/ops.py
index 154813d..6848e3a 100644
--- a/packages/meshbay-node/src/meshbay_node/ops.py
+++ b/packages/meshbay-node/src/meshbay_node/ops.py
@@ -731,6 +731,68 @@ async def set_enabled_apps(state: dict, group_id: str, apps: list[str]) -> dict:
     return {"apps": apps, "group_id": group_id}
 
 
+# ── TMDB config (Videos app) ─────────────────────────────────────────────────
+
+async def set_tmdb_config(state: dict, enabled: bool, token: str | None = None,
+                          language: str | None = None) -> dict:
+    """
+    Whether the node calls TMDB at all, whether it uses a custom API token
+    instead of the shipped default, and in what language it queries TMDB
+    (docs/mediacenter.md §5.5).
+
+    Node-wide (roster.py group_settings, group_id="") rather than per-group
+    like set_member_upload/set_enabled_apps: TMDB is one operator's budget,
+    one credential and one shared cache, not a per-group or per-viewer
+    concern. `token=""` explicitly clears a previously-set custom token
+    (reverts to the shipped default); `token=None` leaves whatever was
+    there unchanged. Same discipline for `language`.
+    """
+    roster = _roster(state)
+    await roster.set_tmdb_config(enabled, token, language, set_by=state.get("node_user_id", ""))
+    state["tmdb_enabled"] = enabled
+    # `token=None` means "leave whatever was there" (§ set_tmdb_config's own
+    # docstring) — so the customized flag only changes when a value (a real
+    # token, or "" to clear one) was actually given.
+    if token is not None:
+        state["tmdb_token_customized"] = bool(token)
+    if language is not None:
+        state["tmdb_language"] = language
+    log.info("TMDB config: enabled=%s custom_token=%s language=%s",
+             enabled, bool(token), language or state.get("tmdb_language", ""))
+    return {
+        "enabled": enabled,
+        "token_customized": state.get("tmdb_token_customized", False),
+        "language": state.get("tmdb_language", ""),
+    }
+
+
+async def set_video_root(state: dict, group_id: str, path: str) -> dict:
+    """
+    Which folder (possibly a subfolder of a shared root) is the Videos app's
+    entry point for this group. Same shape as set_enabled_apps: lives on the
+    node (roster.db), takes effect without a restart, signed by the operator.
+    `path=""` clears it — the Videos tab then asks for one to be chosen
+    before anything (including TMDB enrichment, docs/mediacenter.md §5.2)
+    runs, rather than defaulting to the whole shared index.
+
+    A non-empty path fires (never awaits) a sweep of whatever that folder
+    already contains: the ordinary per-change enrichment path only ever
+    looks at files new since the last broadcast, so anything already sitting
+    in a folder before it became the video_root would otherwise never be
+    picked up.
+    """
+    roster = _roster(state)
+    ctx = _group_ctx(state, group_id)
+    await roster.set_video_root(group_id, path, set_by=state.get("node_user_id", ""))
+    ctx["video_root"] = path
+    log.info("Videos root for group %s: %r", group_id[:8], path)
+    if path:
+        enrich_fn = state.get("enrich_video_root_fn")
+        if enrich_fn:
+            asyncio.ensure_future(enrich_fn(group_id))
+    return {"path": path, "group_id": group_id}
+
+
 # ── Scan settings ────────────────────────────────────────────────────────────
 
 async def set_scan_settings(state: dict, group_id: str, reconcile_interval_secs: float,