v3: fix the queue and re-resolve edge cases in native bandcamp playback

Re-resolving a stream is a network round-trip, and nothing checked that the
player still belonged to that item once it landed. Picking another dump —
or closing the player — while a resolve was in flight let the stale result
swap the queue back; from onError, which resolves with autoplay, it would
also start playing over whatever was chosen instead. A generation counter,
bumped by playQueue/advanceTo/stop, now drops any result that no longer owns
the player, with a separate counter owning the resolving flag so a
superseded resolve can't clear a newer one's spinner.

A track that stays dead after a re-resolve is one track, not one album: the
cooldown path now steps to the next entry and only falls back to the iframe
on the last one. A failed resolve still goes straight to the embed, since
that's an album-wide failure rather than a single bad URL. And a track that
has vanished from the release, or lost its streamable flag to Bandcamp's
free-play cap, no longer resumes track 1 at the dead track's offset — the
findIndex miss resets the offset instead of seeking past the end of another
track.

Clicking the playing row rewound it but never resumed: seekTo only moves
currentTime, so re-selecting a finished or paused track looked like a
no-op. It now resumes as well. Same idea in the compact rich-content card,
whose button advertises "Pause" while active but re-played on click — in
native mode that meant a fresh /api/bandcamp/tracks and a restart from
track 1. It pauses for streams now; embeds have no transport of their own
and keep restarting, as before.

playRichContent reports whether playback actually started, so a native-mode
Bandcamp page with no streams and no stored embedUrl — an artist root, a
/music index, a preorder — is no longer a dead click: the journal card
navigates to the dump as it used to, and the rich-content card opens the
source page.

Also: the tralbum fetch releases the response body on its two error paths.
The endpoint is unauthenticated, so random /track/<slug> URLs would leak a
connection per request while also defeating the cache.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E56F55N7m5GGKKEwoYFJtH

api/services/bandcamp-stream-service.ts

@@ -101,7 +101,11 @@ export async function resolveBandcamp(
       "Could not reach Bandcamp",
     );
   }
+  // Every path out of here that doesn't read the body has to release it, or the
+  // connection stays open until GC. This endpoint is unauthenticated: a caller
+  // hammering random /track/<slug> URLs would otherwise leak one body a request.
   if (!res.ok) {
+    await res.body?.cancel();
     throw new APIException(
       APIErrorCode.SERVER_ERROR,
       502,
@@ -109,6 +113,7 @@ export async function resolveBandcamp(
     );
   }
   if (!(res.headers.get("content-type") ?? "").startsWith("text/html")) {
+    await res.body?.cancel();
     throw new APIException(
       APIErrorCode.SERVER_ERROR,
       502,