feat(mcp): Rust-owned speaking pill with self-contained audio playback

The pill window now surfaces for agent-initiated speech without main-window
involvement. Rust subscribes to /events/speak via a tokio task + reqwest
streaming body (speak_monitor.rs), shows the pill, and forwards events to
the dictate webview over Tauri's event bus. The pill plays audio via a
plain HTMLAudioElement and emits dictate:hide when playback ends. The
pill stays hidden through the ~1 s generation wait and only surfaces when
audio actually starts, with the counter armed at that moment.

Fixes a shared-dict mutation in mcp_server/events.publish() that caused
the second subscriber (Rust speak_monitor) to receive `event: message`
instead of named speak-start/speak-end frames. Also teaches the speak_monitor
parser to handle CRLF framing (sse-starlette default). Main-window
AudioPlayer now skips autoplay for source in {mcp, rest} to avoid
double-play when both windows are alive.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

landing/src/app/capture/page.tsx

@@ -60,12 +60,11 @@ export default function CapturePage() {
           <div className="grid md:grid-cols-3 gap-6">
             <div className="rounded-xl border border-border bg-card/40 backdrop-blur-sm p-6">
               <h3 className="text-[15px] font-semibold text-foreground mb-2">
-                Four STT engines, one picker
+                Whisper, sized for every machine
               </h3>
               <p className="text-sm leading-relaxed text-muted-foreground">
-                Whisper, Whisper Turbo, Parakeet v3, Qwen3-ASR. Pick per-capture — broad
-                multilingual, speed, non-English quality, or cross-platform coverage. All local,
-                all downloadable from inside the app.
+                Base, Small, Medium, Large, and Turbo. Pick per-capture — 99 languages at every
+                tier, all local, all downloadable from inside the app.
               </p>
             </div>
             <div className="rounded-xl border border-border bg-card/40 backdrop-blur-sm p-6">