UI improvements: Reader controls and TTS player

- Add archive/delete/external-link buttons to Reader header
- Create floating TTS player bar with progress slider
- Add 15s skip forward/back controls
- Show current time and duration during playback
- Add busy_timeout to SQLite for concurrent access during build
- Checkpoint WAL after migrations

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/page.tsx

@@ -208,16 +208,26 @@ export default function Home() {
           onToggleFavorite={() =>
             handleToggleFavorite(selectedArticle.id, !selectedArticle.isFavorite)
           }
+          onToggleArchive={() => {
+            handleToggleArchive(selectedArticle.id, !selectedArticle.isArchived);
+          }}
+          onDelete={() => {
+            handleDelete(selectedArticle.id);
+          }}
           onOpenSettings={() => setIsSettingsOpen(true)}
         >
           <TTSControls
             isPlaying={tts.isPlaying}
             isPaused={tts.isPaused}
             isLoading={tts.isLoading}
+            currentTime={tts.currentTime}
+            duration={tts.duration}
+            progress={tts.progress}
             onPlay={tts.play}
             onPause={tts.pause}
             onResume={tts.resume}
             onStop={tts.stop}
+            onSeek={tts.seek}
           />
         </Reader>
         <SettingsPanel