refactor(portals): lift the VOD route's orchestration out of the component

The details route had grown to 864 lines — the repository's hard maximum is
400, and while the file predates the rule, a baselined exemption is not a
budget to spend.

Three component-provided services now hold what the component was
accumulating: `VodDetailsMultiSourceUiService` (the playback-evidence latch,
the caption, the primary button's position, source actions and the failover
toast), `VodDetailsSimilarService` (the rail and its cross-portal lookup), and
`VodDetailsDownloadsService`. The component keeps its public API, so the
template and the existing specs are untouched. 864 -> 566 lines.

The downloads move also fixes a latent bug: `downloadVod` and `playFromLocal`
read `route.snapshot.params`, which is stale once the router reuses this
component for detail-to-detail navigation (the Similar rail) — so a download
started from a film reached that way fetched the previous one. They now read
the same route-params signal everything else uses, with a regression test.

Also from review: pins are applied on the FRESH-import path too. A new
playlist has no content when the archive is read, so its user state is parked
and replayed after the import — the merge path I wired first never ran there,
and every pin was dropped. A failed pin write now propagates instead of being
ignored: the backup entry is reported failed, and the parked state is kept so
a transient failure can be retried rather than silently losing the preference.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/architecture/vod-multi-source.md

@@ -478,6 +478,14 @@ Two things read it, and they must agree: the "Playing from" caption, and the
 source row's badge — which reads `Current` when a source is merely selected and
 `Playing` once one really is.
 
+## Where the route's code lives
+
+`VodDetailsRouteComponent` is a thin host. The multi-source concerns it grew
+live in `VodDetailsMultiSourceUiService` (component-provided): the
+`playbackLive` evidence, the caption, the primary button's position, the
+source actions, and the failover toast. The "Similar" rail and offline
+downloads sit in their own component-provided services beside it.
+
 ## Backup
 
 Pins ride along with playlist backup, under the playlist they point at, as the