feat: harden Flow cold-start/force-quit and polish macOS dictation UX

Fix cold-start overlay recursion that overflowed the main-thread stack when
recording began while the ready overlay was still up; also remove temporary
on-screen Flow DEBUG panels after the orange-mic investigation, and land the
macOS overlay/catalog/layout polish plus related Flow recovery hardening.

CHANGELOG.md

@@ -7,7 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **macOS dictation overlay**: a bottom-centered floating pill appears for any recording path (global hotkey, menu bar, or main window) — shows listening / transcribing state, a stronger live waveform, a one-line live transcript preview (partials when chunked ASR runs), front-app name, and a stop control, then briefly confirms success before fading out without stealing focus. / **macOS 听写浮层**：任意录音路径（全局热键、菜单栏或主窗口）都会在屏幕底部居中出现胶囊浮层——显示聆听 / 识别状态、更强的实时波形、单行转写预览（分块识别时显示 partial）、前台应用名与停止按钮，成功后短暂确认再淡出，且不抢前台焦点。
+- **macOS Option-key picker**: Settings → Input lets you choose Left / Right / Either Option as the hold-to-talk key, so the shortcut can avoid conflicts with other apps. / **macOS Option 键选择**：设置 → 输入与快捷键可选择左 / 右 / 任一 Option 作为按住听写键，避免与其他应用冲突。
+
+### Changed
+- **Removed temporary Flow DEBUG panels**: the on-screen App Group / session debug text boxes on Home and the keyboard extension are gone now that the orange-mic investigation is closed. / **移除临时 Flow DEBUG 面板**：橙色麦克风排查结束后，首页与键盘扩展上的 App Group / 会话调试文本框已去掉。
+- **macOS local ASR catalog**: removed offline Paraformer; SenseVoice / Qwen3 0.6B / Qwen3 1.7B now show Fastest / Most balanced / Best quality badges (users still on Paraformer migrate to Qwen3 0.6B). / **macOS 本地 ASR 目录**：移除 offline Paraformer；SenseVoice / Qwen3 0.6B / Qwen3 1.7B 分别标注速度最快 / 最平衡 / 质量最好（仍选 Paraformer 的用户迁移到 Qwen3 0.6B）。
+- **macOS visual system**: full-app redesign around the brand line “Speak it. It’s typed.” / 「开口即文字。」— grouped sidebar, restrained accent selection, asymmetric Home stats (chars as hero), unified page headers, quieter status footer, and clearer dark-mode card elevation. / **macOS 视觉体系**：围绕品牌句「开口即文字。」/ “Speak it. It’s typed.” 做全 App 设计升级——侧栏分组、克制的选中态、首页不对称统计（字数主卡）、统一页头、降权状态栏，以及更清晰的暗色卡片层次。
+- **macOS Home stat cards**: the hero word-count card is now a full-width horizontal bar sized to its content (icon + label + big number) instead of a tall card stretched to match its neighbors, removing the large dead space below the number; the "Recent" list was removed from Home since it duplicated the History page. / **macOS 首页统计卡**：字数主卡改为按内容自适应高度的满宽横条（图标+标题+大数字），不再被拉伸到与相邻卡片等高、留出大片空白；首页底部与历史页重复的「最近」列表已移除。
+- **macOS page margins**: Home / History / Dictionary / Settings share `pageHorizontalInset` on titles and scroll *content*; ScrollViews / Forms stay full-bleed so the scrollbar sits on the window edge, while cards stay aligned with the page title. Settings keeps native grouped Form for control layout. / **macOS 页边距**：首页 / 历史 / 词库 / 设置在标题与滚动*内容*上共用 `pageHorizontalInset`；ScrollView / Form 通栏使滚动条贴窗口右缘，卡片仍与页标题对齐。设置保留原生分组 Form 以保证控件排版。
+
 ### Fixed
+- **Cold-start overlay recursion crash**: dismissing the ready overlay while an utterance is already recording no longer recurses `refreshHostReady` → `reconcile` → `dismiss` on the main thread until stack overflow (`EXC_BAD_ACCESS`). Handoff flags are cleared before any refresh. / **冷启动浮层递归崩溃**：就绪浮层仍在时若已开始录音，不再在主线程上递归 `refreshHostReady` → `reconcile` → `dismiss` 直至栈溢出（`EXC_BAD_ACCESS`）；交接标志会在任何 refresh 之前先清除。
+- **macOS Qwen3 “language” garbage transcript**: Sherpa Qwen3 results that still include the model scaffold (`language Chinese<asr_text>…`) are now stripped to the spoken text; incomplete outputs that stop at the bare word `language` are treated as empty instead of being inserted. / **macOS Qwen3「language」乱码转写**：Sherpa Qwen3 结果若仍带模型脚手架（`language Chinese<asr_text>…`）会剥到真实口语文案；不完整输出停在单词 `language` 时按空结果处理，不再插入。
+- **macOS local ASR silence garbage output**: dictating with no speech (silence) on a Sherpa-backed local model (SenseVoice/Qwen3/Paraformer) no longer inserts the raw JSON result line (`{"lang": "", "emotion": "", ...}`) as the transcript — it now correctly reports "no speech recognized". / **macOS 本地识别静音乱码**：使用 Sherpa 本地模型（SenseVoice/Qwen3/Paraformer）听写时若未检测到语音，不再把原始 JSON 结果行（`{"lang": "", "emotion": "", ...}`）当作转写文本插入，现在会正确提示「没有识别到语音」。
 - **Force-quit mic release**: on termination the host app now synchronously stops `AVAudioEngine`, deactivates `AVAudioSession`, and ends Live Activities (Dynamic Island + Lock Screen) in `applicationWillTerminate`, reducing “microphone in use” errors after reopening. / **强杀麦克风释放**：进程终止时在 `applicationWillTerminate` 内同步停止 `AVAudioEngine`、释放 `AVAudioSession` 并结束 Live Activity（灵动岛 + 锁屏），降低强杀后重开提示麦克风被占用的概率。
 
 ## [0.5.2] - 2026-07-09