Dashboard detail, library filtering/pagination, simplified playlist times,

job descriptions

Dashboard: format breakdown (FLAC/MP3/etc. counts), approximate library
size (bitrate*length/8, same approximation `beet stats` itself uses --
verified to match its "100.5 GiB" output exactly against the real
library), and a credential auth-state summary per scope (configured y/n
plus, for Bandcamp, cookie expiry parsed locally from the stored cookie
jar -- deliberately not a live network probe like pipeline-status.sh's
Qobuz check, since this renders on every dashboard load).

Library: was one unfiltered page dumping all 4072 tracks. Added search
(artist/title/album), playlist and format filter dropdowns, and real
SQL-level pagination (LIMIT/OFFSET, not fetch-everything-then-slice).
beets_service gained count_items()/distinct_formats() to support this.

Playlists: cron_expr is still the stored/scheduled representation, but the
UI now shows and edits a plain daily time picker instead of raw cron
syntax -- every playlist schedule today is a simple daily HH:MM anyway.
playlist_service.cron_to_time()/time_to_cron() convert at the router
boundary; verified round-trip against all real playlist cron values.

Jobs: each maintenance job now shows a short one-line description of what
it actually does (MAINTENANCE_JOB_DESCRIPTIONS), and "next run" is
formatted consistently with playlists' time style (HH:MM, with a day
qualifier for non-today runs -- maintenance jobs can be weekly/monthly,
unlike playlists' plain daily schedule).

Verified end-to-end against the real production data (4072 tracks, 100.5
GiB, real credentials): stats/format-breakdown/search/pagination all
correct, all 7 credential scopes report configured with Bandcamp's real
cookie expiry (325 days), and a full authenticated page-render sweep
(dashboard, library with every filter combination, playlist detail,
jobs) all returned 200 with no template errors.

app/templates/playlists/detail.html

@@ -19,8 +19,9 @@
   <form method="post" action="/playlists/{{ playlist.id }}">
     <label class="checkbox-field"><input type="checkbox" name="active" value="true" {{ "checked" if playlist.active }}> Active</label>
     <div class="field">
-      <label for="cron_expr">Cron schedule</label>
-      <input type="text" id="cron_expr" name="cron_expr" value="{{ playlist.cron_expr or '' }}" placeholder="0 1 * * *">
+      <label for="sync_time">Sync time (daily)</label>
+      <input type="time" id="sync_time" name="sync_time" value="{{ sync_time }}">
+      <span class="hint">Leave blank for unscheduled/manual-only.</span>
     </div>
     <label class="checkbox-field"><input type="checkbox" name="no_m3u" value="true" {{ "checked" if playlist.no_m3u }}> Skip M3U</label>
     <div class="field wide">

app/templates/playlists/index.html

@@ -11,14 +11,14 @@
 <div class="table-wrap scroll">
   <table>
     <thead>
-      <tr><th>Name</th><th>Active</th><th>Cron</th><th>No M3U</th><th></th></tr>
+      <tr><th>Name</th><th>Active</th><th>Sync time</th><th>No M3U</th><th></th></tr>
     </thead>
     <tbody>
       {% for p in playlists %}
       <tr>
         <td><a href="/playlists/{{ p.id }}">{{ p.name }}</a></td>
         <td>{% if p.active %}<span class="badge badge-success">active</span>{% else %}<span class="badge badge-muted">paused</span>{% endif %}</td>
-        <td class="muted mono">{{ p.cron_expr or "unscheduled" }}</td>
+        <td class="muted mono">{{ sync_times.get(p.id) or "unscheduled" }}</td>
         <td class="muted">{{ "yes" if p.no_m3u else "no" }}</td>
         <td class="actions-cell">
           <form method="post" action="/playlists/{{ p.id }}/delete" class="inline"
@@ -51,9 +51,9 @@
       <input type="text" id="spotify_url" name="spotify_url" required placeholder="https://open.spotify.com/playlist/...">
     </div>
     <div class="field">
-      <label for="cron_expr">Cron schedule</label>
-      <input type="text" id="cron_expr" name="cron_expr" placeholder="0 1 * * *">
-      <span class="hint">5-field cron. Leave blank for unscheduled/manual-only.</span>
+      <label for="sync_time">Sync time (daily)</label>
+      <input type="time" id="sync_time" name="sync_time">
+      <span class="hint">Leave blank for unscheduled/manual-only.</span>
     </div>
     <label class="checkbox-field"><input type="checkbox" name="no_m3u" value="true"> Skip M3U generation (e.g. "liked songs")</label>
     <button type="submit" class="btn btn-primary">Add playlist</button>