Add recently played tracking with shows and broadcasts

- sql/schema.sql: shows, broadcasts and played_tracks tables, seeded
  with the five shows
- cli/poll_icecast.php: cron-run poller that records broadcasts and
  tracks every 15 seconds while streaming; tracks are cleared ten
  minutes after a broadcast ends
- cli/set_show.php: queue the next show, or assign one to the live
  broadcast
- recently_played.php: track history rows for live.php, with album art
  and album title linking to Last.fm
- live.php: recently played list, show name in heading, and per-show
  header background
- includes/icecast.php: Icecast parsing, album art and Last.fm helpers
  shared by now_playing.php and the poller
- includes/db.php: use UTC for the database session

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

CLAUDE.md

@@ -19,12 +19,29 @@ This repo covers the **frontend only** — the public-facing website. Icecast co
 
 - [index.php](index.php) — Main page. Contains the audio player, now-playing widget, upcoming schedule section, and about section. Show information is updated here manually before each broadcast.
 - [now_playing.php](now_playing.php) — Fetches the currently playing track from the Icecast JSON status API and returns it as HTML. Called by the frontend every 15 seconds via `setInterval`.
+- [live.php](live.php) — Page for active broadcasts. Player on the left, recently played list on the right; the header background and heading change with the current show.
+- [recently_played.php](recently_played.php) — Returns the current broadcast's track history as table rows for `live.php`.
+- [includes/icecast.php](includes/icecast.php) — Shared Icecast fetching/parsing, album art lookup and Last.fm link helpers.
+- [includes/db.php](includes/db.php) — `getDB()` returns a shared PDO connection (session time zone UTC).
+- [includes/broadcasts.php](includes/broadcasts.php) — Broadcast lifecycle and track history logic.
+- [cli/poll_icecast.php](cli/poll_icecast.php) — Cron-run poller that records broadcasts and tracks.
+- [cli/set_show.php](cli/set_show.php) — Sets which show is airing next (or now).
 
 ## Architecture
 
 - **Backend:** PHP only. No Composer, no package manager, no build step.
 - **Frontend:** HTML5 UP Strata template with custom CSS additions. No npm, no webpack, no preprocessor — edit CSS directly in `assets/css/main.css` or inline `<style>` blocks.
-- **Now-playing:** `index.php` fetches `now_playing.php` via JavaScript every 15 seconds and injects the result into `#now-playing`. The fetch uses `arrayBuffer` + `TextDecoder` to handle the UTF-8 encoding correctly on the client side.
+- **Now-playing:** `index.php` and `live.php` fetch `now_playing.php` via JavaScript every 15 seconds and inject the result into `#now-playing`. The fetch uses `arrayBuffer` + `TextDecoder` to handle the UTF-8 encoding correctly on the client side.
+
+## Database
+
+MariaDB on localhost. Credentials live in `config/db_credentials.php`, which is gitignored and uploaded to the server separately; `config/db_credentials.example.php` is the template. Schema is in [sql/schema.sql](sql/schema.sql):
+
+- `shows` — the shows, with an optional `background_image` (filename in `images/backgrounds/`).
+- `broadcasts` — one row per streaming session: pending (queued by `cli/set_show.php`), live, or ended.
+- `played_tracks` — tracks per broadcast. Cleared ten minutes after the broadcast ends; no long-term history is kept.
+
+`cli/poll_icecast.php` runs from cron every minute and polls Icecast four times, 15 seconds apart. A broadcast starts when the stream comes online and ends after five minutes unseen (so brief drop-outs don't split a show). Before going live, run `php cli/set_show.php <slug>` to choose the show.
 
 ## Icecast Integration
 
@@ -35,7 +52,7 @@ The status API returns JSON with track metadata under `icestats.source`. The `so
 
 ## Known Encoding Quirk
 
-Icecast double-encodes track metadata as Latin-1 interpreted as UTF-8. The fix in [now_playing.php:23-24](now_playing.php#L23-L24) deliberately converts the string from UTF-8 to ISO-8859-1 to strip the outer encoding layer and recover the correct UTF-8 byte sequence. Do not remove or "simplify" this conversion — it is intentional and necessary for non-ASCII characters (accented names, etc.) to display correctly.
+Icecast double-encodes track metadata as Latin-1 interpreted as UTF-8. The fix in `decodeMetaField()` in [includes/icecast.php](includes/icecast.php) deliberately converts the string from UTF-8 to ISO-8859-1 to strip the outer encoding layer and recover the correct UTF-8 byte sequence. Do not remove or "simplify" this conversion — it is intentional and necessary for non-ASCII characters (accented names, etc.) to display correctly.
 
 ## Deployment