feat: v0.3.0 — history, 4-button search, options page, newtab override

Web Store submission target. Mirrors rangerhq-radio's track-history pattern
(inc/history.php) so the family stays coherent across surfaces.

Highlights
- New Tab Page override (Tier 2.5) — Chrome's default new tab replaced with
  a RangerHQ-branded landing showing the player, current track, quick chips,
  searchable browse list, and now history + favourites tabs.
- Track history + favourites — capped FIFO 500, dedup against last entry,
  skip "(unknown)" artist (SomaFM dead-air). Stored in chrome.storage.local
  under tuner.history + tuner.favourites.
- 4-button search per entry — Spotify / YouTube / Apple Music / Bandcamp.
  Pure public-search-URL link-outs in a new tab, NO auth, NO API keys, NO
  quota, NO third-party SDK embedded.
- Options page (chrome://extensions → details → options) — live stats,
  history cap slider (50-500), Clear history / Clear favourites / Clear
  EVERYTHING buttons, About panel with Gitea + davidtkeane.com links.
- Popup nav row — Open in tab / History (#hash deep link) / Settings,
  using chrome.tabs.create + chrome.runtime.openOptionsPage. No new perms.
- Cross-surface sync — popup ↔ newtab listen on chrome.storage.onChanged
  for tuner.currentStationId / tuner.isPlaying / history / favourites.
- Storage gateway — offscreen doc can't reliably reach chrome.storage in
  some Chrome versions, so it sends LOG_TRACK_REQUEST to the SW which
  does the write. history.js also defensively guards every storage call.
- Metadata latency fix — polling now starts immediately on PLAY, in
  parallel with audio buffer fill. First track display drops from
  ~10-15s to ~1-2s.

Permissions unchanged
- Still ["offscreen", "storage"] + somafm.com host only.
- chrome.tabs.create works on our own extension URLs without "tabs" perm.
- No webRequest, no <all_urls>, no third-party SDK.

Bumped from 0.1.0 (last tag on Gitea) directly to 0.3.0.
v0.2.0 (newtab + clock) was a working local build but never tagged;
its features ship together with v0.3.0 in this single commit.

src/popup/popup.css

@@ -245,11 +245,55 @@ html, body {
   font-size: 12px;
 }
 
+/* Nav — quick-link row above the footer */
+.tuner-nav {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  background: var(--bg-soft);
+  border-top: 1px solid #000;
+  gap: 1px;
+}
+
+.tuner-nav-btn {
+  background: var(--bg-soft);
+  color: var(--fg-muted);
+  border: 0;
+  padding: 8px 4px;
+  font: inherit;
+  font-size: 11px;
+  font-weight: 500;
+  cursor: pointer;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 3px;
+  font-family: inherit;
+}
+
+.tuner-nav-btn:hover {
+  background: var(--bg-row);
+  color: var(--fg);
+}
+
+.tuner-nav-btn:active {
+  background: var(--bg-row-hi);
+}
+
+.tuner-nav-icon {
+  font-size: 14px;
+  line-height: 1;
+  color: var(--accent);
+}
+
+.tuner-nav-label {
+  letter-spacing: 0.3px;
+}
+
 /* Footer */
 .tuner-footer {
   padding: 6px 12px;
   background: var(--bg-soft);
-  border-top: 1px solid #000;
+  border-top: 1px solid var(--bg-row);
   font-size: 10px;
   color: var(--fg-muted);
   text-align: center;