0.6.12: Redesign the dedup review table for faster, more accurate scanning

The keep/delete columns were raw paths in a fixed-width cell: ellipsis-
truncated, full text only on hover. Slow to scan (mousing over every
row to read the song name) and, once "fixed" with a tag-derived title/
artist header in a first pass of this change, actively worse for the
thing dedup review actually needs -- confirming two files are really
the same recording. Tags can be wrong; the filename on disk can't.

New layout: each candidate gets a title row (song title, large,
unclipped -- parsed from beets' known singleton path template,
Artist/Album/Title.ext) followed by a compact detail row. The detail
row shows a color-coded format pill (FLAC/MP3/etc, matching the same
quality judgment dedup-library.sh's rank_file() already makes) and the
full relative file path, always rendered as visible text -- never
hover-only -- so a real difference in filename, album, or folder is
still plainly visible even when tags line up. Shared artist collapses
onto the title row so it isn't repeated per side; a colored left rail
marks which side survives without having to read the words.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/static/style.css

@@ -475,11 +475,60 @@ tbody tr:hover { background: rgba(167, 139, 250, 0.055); }
 tbody td.actions-cell { display: flex; gap: 0.5rem; flex-wrap: wrap; }
 
 .dedup-table { table-layout: fixed; }
-.dedup-table .path-cell {
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-  max-width: 0; /* forces the cell to respect the colgroup width instead of the content's natural width */
+
+/* Each candidate is its own <tbody> (title row + detail row) so the pair
+   highlights together on hover, and so :hover can bubble from either row
+   up to the shared group without JS. That means every detail row is now
+   a tbody's last-child, which would otherwise strip the separator between
+   one candidate and the next (the generic `tbody tr:last-child` rule above
+   assumed one shared tbody) -- restore it here, and only drop it for the
+   actual last group in the table. */
+.dedup-table .dedup-row-group:hover td { background: rgba(167, 139, 250, 0.06); }
+.dedup-table .dedup-detail-row td { border-bottom: 1px solid var(--border); }
+.dedup-table .dedup-row-group:last-of-type .dedup-detail-row td { border-bottom: none; }
+
+.dedup-title-row td { padding: 0.75rem 1.1rem 0.2rem; border-bottom: none; }
+.dedup-detail-row td { padding-top: 0.15rem; }
+
+.dedup-title {
+  font-family: var(--font-display);
+  font-size: 1.02rem;
+  font-weight: 700;
+  color: var(--fg);
+  line-height: 1.35;
+  overflow-wrap: anywhere;
+}
+.dedup-title-alt { font-weight: 400; color: var(--muted); }
+
+.dedup-context { font-size: 0.8rem; margin-top: 0.15rem; }
+
+/* A thin colored rail on each side echoes the keep/delete verdict itself --
+   green for the copy that survives, muted-pink for the one on the chopping
+   block -- so which side is which reads before you've even read the words. */
+.dedup-side {
+  display: flex;
+  align-items: center;
+  gap: 0.55rem;
+  padding-left: 0.65rem;
+  border-left: 2px solid transparent;
+  min-height: 1.6rem;
+}
+.dedup-side-keep { border-left-color: var(--status-success); }
+.dedup-side-delete { border-left-color: var(--status-danger); }
+
+.dedup-side-size { font-size: 0.78rem; white-space: nowrap; flex-shrink: 0; }
+
+/* The actual filename/path -- always visible, never truncated. Tags can be
+   wrong; this is the ground truth for judging whether two files are really
+   the same recording, so it can't be hover-only the way it was in the first
+   pass of this redesign. */
+.dedup-side-path {
+  padding-left: 0.65rem;
+  margin-top: 0.2rem;
+  font-size: 0.78rem;
+  color: var(--muted-2);
+  overflow-wrap: anywhere;
+  line-height: 1.4;
 }
 
 .empty-row td { padding: 2.5rem 1rem; text-align: center; }