Overhaul card-data ingest: filter art cards, segmented cancellable progress

- Exclude Scryfall Art Series cards (layout "art_series") from ingest —
  they aren't playable cards and were polluting search results.
- Replace the coarse per-stage progress text with a byte-accurate,
  weighted multi-segment progress bar (Index / Card data / Printings /
  Indexing) that fills as one continuous bar instead of swapping per
  stage; segment weights are computed from the real download sizes
  reported by Scryfall's bulk-data index (the download responses
  themselves are chunked with no Content-Length to rely on).
- Add a Cancel button, wired through a new CancelToken checked once per
  parsed record so cancellation lands almost instantly.
- Fix a related correctness bug this surfaced: ingest used to delete the
  existing reference.db before writing its replacement, so a cancelled
  or crashed update left the app with no card database at all. It now
  builds into a temp file and only atomically replaces reference.db on
  full success.
- Split the topbar's single "Choose library…" action into separate
  "Open Library…" (existing file) and "New Library…" (save-dialog for a
  new file) buttons.

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

src/styles.css

@@ -292,14 +292,108 @@ select:focus {
   text-overflow: ellipsis;
   white-space: nowrap;
 }
-.progress {
-  color: var(--accent-hover);
-  font-size: 12px;
-  font-weight: 500;
-}
 .spacer {
   flex: 1;
 }
+
+/* Ingest (card-data download/index) progress: one multi-segment bar spanning
+   all stages, below the topbar. */
+.ingest-bar {
+  padding: 8px 18px 10px;
+  background: var(--bg-elev);
+  border-bottom: 1px solid var(--border-soft);
+  font-size: 12px;
+}
+.ingest-bar-head {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  margin-bottom: 6px;
+}
+.ingest-bar-message {
+  color: var(--muted);
+  font-family: ui-monospace, "SF Mono", Menlo, monospace;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.ingest-bar-cancel {
+  flex-shrink: 0;
+  padding: 3px 10px;
+  font-size: 11px;
+  color: var(--muted);
+}
+.ingest-bar-cancel:hover {
+  color: var(--danger);
+  border-color: var(--danger);
+}
+.ingest-bar-dismiss {
+  flex-shrink: 0;
+  background: none;
+  border: none;
+  color: var(--faint);
+  cursor: pointer;
+  padding: 2px 6px;
+  font-size: 13px;
+}
+.ingest-bar-dismiss:hover {
+  color: var(--text);
+}
+
+.ingest-segments {
+  display: flex;
+  gap: 4px;
+}
+.ingest-segment {
+  min-width: 0;
+}
+.ingest-segment-track {
+  height: 6px;
+  border-radius: 999px;
+  background: rgba(0, 0, 0, 0.3);
+  overflow: hidden;
+}
+.ingest-segment-fill {
+  height: 100%;
+  border-radius: 999px;
+  background: var(--border);
+  transition: width 0.2s ease;
+}
+.ingest-segment.active .ingest-segment-fill {
+  background: linear-gradient(90deg, var(--accent-hover), var(--accent));
+}
+.ingest-segment-label {
+  display: block;
+  margin-top: 3px;
+  font-size: 10px;
+  color: var(--faint);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.ingest-segment.active .ingest-segment-label {
+  color: var(--accent-hover);
+  font-weight: 600;
+}
+
+.ingest-bar-done .ingest-segment-fill {
+  background: var(--success);
+}
+.ingest-bar-done .ingest-bar-message {
+  color: var(--success);
+}
+.ingest-bar-error .ingest-segment-fill {
+  background: var(--danger);
+}
+.ingest-bar-error .ingest-bar-message {
+  color: var(--danger);
+}
+.ingest-bar-cancelled .ingest-segment-fill {
+  background: var(--warn);
+}
+.ingest-bar-cancelled .ingest-bar-message {
+  color: var(--warn);
+}
 .content {
   flex: 1;
   overflow: auto;