feat(flow): harden host handoff, session UX, and Live Activity brand

- fix(keyboard): drop unusable extensionContext.open; report the real
  result of UIApplication.open and cancel the start watchdog immediately
  on failure with clear "open OSGKeyboard" guidance instead of a 30s spin
- feat(capture): recover from audio route changes (AirPods/wired headset
  plug-unplug) and phone-call interruptions by rebuilding the engine/tap
  against the live hardware format
- feat(home): add a "Start" button in the Home footer when a session is
  inactive and permissions are granted (no-jump manual restart)
- feat(hostapps): expand the return whitelist to 46 apps (Signal, Zoom,
  Instagram, X, Douyin, Zhihu, Bilibili, Things, Firefox, ...) with
  en/zh-Hans names and synced LSApplicationQueriesSchemes
- feat(island): use a "ready" checkmark instead of a mic glyph while idle
  and set a staleDate so an orphaned Live Activity fades after a force-quit
- feat(coldstart): use the template OSG brand mark instead of a system
  waveform glyph in the cold-start overlay
- perf(keyboard): rely on Darwin notifications as the primary session
  signal and drop the fallback poll from 1s to 3s
- fix(keyboard): remove the redundant "Start" text button next to the
  inactive-session hint on the keyboard
- docs: correct the per-take cap to 210s (3.5 min) and document that
  force-quitting no longer resurrects the session (tracker + READMEs)

README.md

@@ -18,7 +18,7 @@
 OSGKeyboard is a free, source-available alternative to commercial voice-input tools. It runs as a **Custom Keyboard Extension** on iOS, so you can use it in **any app** — Messages, Notes, Mail, WeChat, ChatGPT, Claude, Cursor, you name it.
 
 1. Tap the mic to start recording
-2. Speak naturally (up to 60 seconds per take)
+2. Speak naturally (up to 3.5 minutes / 210 seconds per take)
 3. Tap again to stop — the AI polishes your words into clean text and inserts at the cursor
 
 Audio is transcribed **on-device** by Apple's `SpeechAnalyzer` + `DictationTranscriber` (iOS 26+). Only the **polished transcript** is sent to your chosen cloud LLM. **No audio ever leaves your phone.**
@@ -29,7 +29,7 @@ Under the hood, OSGKeyboard uses a **Flow session model**: a long-lived audio se
 
 ## Features
 
-- 🎙 **Tap-to-toggle recording** with a Typeless-style circular mic button, 60-second per-take cap with live countdown
+- 🎙 **Tap-to-toggle recording** with a Typeless-style circular mic button, 3.5-minute (210s) per-take cap with live countdown
 - 🧠 **On-device ASR** (`SpeechAnalyzer` + `DictationTranscriber`, iOS 26+)
 - ✍️ **AI polishing** — adds structure, punctuation, fixes grammar, optionally produces lists
 - 🧩 **Local + cloud polish toggle** — local engine is ASR-only by default; opt into a post-ASR cloud polish step (DeepSeek by default) when the iOS speech recognition isn't strong enough for your environment (noisy far-field audio, strong accents, etc.)
@@ -168,7 +168,8 @@ To set it as the new default for first-time users, also bump the `defaultProvide
 - **~60 MB memory cap** for the keyboard extension (iOS sandbox). The Flow session is hosted in the main app, so audio buffers and ASR models live there, not in the extension.
 - **"Allow Full Access" required.** Without it, the keyboard can't reach the microphone or make network requests for cloud polish.
 - **Password fields and some `WKWebView` textareas** are blocked by iOS itself — not something we can work around.
-- **60-second per-take cap.** A long take is automatically stopped and dispatched for transcription; a new take can be started immediately.
+- **3.5-minute (210s) per-take cap.** A long take is automatically stopped and dispatched for transcription; a new take can be started immediately.
+- **Force-quitting the host app does not resurrect the old session.** The Live Activity is cleared immediately; the next time you open the app (with permissions granted) a fresh voice session starts automatically.
 - **3-minute per-utterance ASR cap.** If you exceed it, the pipeline gracefully splits into multiple stitched chunks.
 - **No on-device LLM polish.** The local engine is ASR-only; "AI polish" is always cloud-based and configurable. On-device model support was explored in v0.2.0 and rolled back in v0.2.1 to keep the dependency surface at zero SPM packages.
 - **URL scheme `osgkeyboard://`** can be opened by any app on the device. We don't trust it for anything beyond "wake the host app and (re)start the Flow session"; it never carries your API key or other secrets.