Homepage: seamless theme music that keeps playing on /members/

Adds the eom.dev theme (Strudel) as a 16-bar Web Audio loop (Opus, AAC
fallback) with a Theme on/off button. Playback starts on the first
interaction unless the visitor turned it off. While it plays, links
between the homepage and membership pages are fetched and swapped in
place, so the music doesn't restart; sign-in, checkout, billing and
forms remain real navigations.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -84,6 +84,22 @@ can use the permanent channel and playlist links. Requests use 10-second timeout
 and a 2 MiB response limit. Titles are rendered as text, and watch/thumbnail URLs
 are restricted to the PeerTube origin. No descriptions, HTML, or players are embedded.
 
+### Theme music
+
+The homepage plays the eom.dev theme (composed in Strudel) as a seamless 16-bar
+loop: `htdocs/static/theme-player.mjs` with `htdocs/static/audio/eom-theme-loop.ogg`
+(Opus) and an AAC `.m4a` fallback. Web Audio loops it without a gap. Browsers
+block sound until the first click or key press, so it starts then unless the
+visitor switched it off with the "Theme" button (remembered in localStorage).
+
+While it plays, links between the homepage and `/members/` pages are fetched
+and swapped into the same document, so the music does not restart on the
+membership page. Forms, sign-in, checkout, billing and other sites stay normal
+navigations (`HARD_NAV` in the module), and with the music off every link is a
+normal navigation. The membership templates do not load the player; a visitor
+who opens `/members/` directly gets no music. Sources and longer versions are
+kept outside this repository (`eom-theme.strudel.js`).
+
 ### Local preview and content checks
 
 With Node.js 24 or later, run `node scripts/preview.mjs` from this repository