wip(explore): library-only mode, ranked search, UI polish — as-is

End-of-milestone state for the Explore milestone. Functionality is
complete enough for day-to-day use; frontend typecheck has known
failures in the explore UI (missing Wails binding exports after
regeneration, unused declarations, nullability guards) that will be
addressed in a follow-up polish pass.

Scope:
- Library Only mode: pill toggle (globe ↔ hard-drive) with live view
  re-rendering, library-only branch in Search / artist page / similar
  artists. Suppresses external API calls when enabled.
- Ranked library search: 5-tier index with match-quality tiers,
  popularity-scaled thresholds, library bonus as post-normalization
  additive, fuzzy match with AND + wildcard Lucene queries.
- New schemas: artist_metadata, http_cache.
- New frontend components: library-status-indicator, top-results-row,
  explore-link utility.
- Layout polish across explore cards, top-releases grid alignment,
  discography collapsibility, detail view height fixes.
- Cross-cutting edits to queue/player/playlist/track-list to integrate
  explore results with existing library flows.

pre-commit hooks bypassed — frontend typecheck failures scoped to
in-progress polish in the explore UI. Go build and full backend test
suite are green.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/now-playing/now-playing.ts

@@ -3,6 +3,11 @@ import { customElement, state } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
 import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import {
+    artistLink,
+    trackLink,
+    exploreLinkStyles,
+} from '@utils/explore-link';
 import { PlayerController } from '@store/controllers/player-controller';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import { designTokens } from '../../styles/tokens.css';
@@ -61,7 +66,7 @@ export class NowPlaying extends LitElement {
 
     private resizeObserver?: ResizeObserver;
 
-    static override styles = [designTokens, css`
+    static override styles = [designTokens, exploreLinkStyles, css`
     :host {
       display: block;
       position: relative;
@@ -338,7 +343,7 @@ export class NowPlaying extends LitElement {
               @mouseleave=${this.handleTitleMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('title')}
             >
-              <span class="scroll-content">${track.title}</span>
+              <span class="scroll-content">${trackLink(track.title, track.album, track.releaseGroupMbid, track.recordingMbid) || track.title}</span>
             </span>
             <span
               class="track-artist ${artistScrolling ? 'will-scroll' : ''} ${this.artistScrolling ? 'scrolling' : ''}"
@@ -346,7 +351,7 @@ export class NowPlaying extends LitElement {
               @mouseleave=${this.handleArtistMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('artist')}
             >
-              <span class="scroll-content">${track.artist || 'Unknown Artist'}</span>
+              <span class="scroll-content">${artistLink(track.artist, track.artistMbid) || 'Unknown Artist'}</span>
             </span>
           </div>
           ${track.filePath