v3: native bandcamp playback and a queue in the global player

The player now holds a queue instead of a single item, so albums play
through and single tracks share the same code path. Adds a "stream" item
kind for expiring, remotely-hosted sources: Bandcamp signs its mp3 URLs
for ~24h, so an item carries the page it came from and re-resolves itself
on error or on a stale restored session, falling back to the iframe embed
if that fails too.

Gated behind GERBEUR_BANDCAMP_PLAYER (default "embed"), injected into a
meta tag the same way as site-name/site-emoji.

Also: player header gains artwork and a subtitle, volume persists across
queue advances and reloads, and cross-origin streams get a plain seek bar
rather than a waveform that can never decode.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SbtjNsT5wvuABnfqhegZEJ

api/lib/static.ts

@@ -1,5 +1,5 @@
 import { Context, Next, send } from "@oak/oak";
-import { OG_SITE_NAME, SITE_EMOJI } from "../config.ts";
+import { BANDCAMP_PLAYER, OG_SITE_NAME, SITE_EMOJI } from "../config.ts";
 import { emojiToCodepoint } from "./site-icons.ts";
 
 const ICON_VERSION = emojiToCodepoint(SITE_EMOJI);
@@ -13,7 +13,8 @@ async function serveIndexHtml(
   const html = raw
     .replaceAll("__SITE_NAME__", OG_SITE_NAME)
     .replaceAll("__SITE_EMOJI__", SITE_EMOJI)
-    .replaceAll("__ICON_VERSION__", ICON_VERSION);
+    .replaceAll("__ICON_VERSION__", ICON_VERSION)
+    .replaceAll("__BANDCAMP_PLAYER__", BANDCAMP_PLAYER);
   context.response.type = "text/html";
   context.response.body = html;
 }