feat(tts): add TTS buttons to PlanView and FilesView markdown preview with configurable input mode (#1443)

Add TTS controls to markdown preview surfaces so users can listen to plans
and markdown files directly from the preview toolbar.

Changes:
- Add read-aloud / stop buttons to PlanView markdown preview.
- Add read-aloud / stop buttons to FilesView markdown preview for markdown files.
- Respect the existing showMessageTTSButtons preference in both preview views.
- Add a persisted ttsInputMode setting with sanitized/raw modes.
- Keep sanitized mode as the default for backward compatibility.
- Allow raw markdown only for server TTS providers that can handle markdown.
- Always use sanitized text for browser and macOS say fallback paths.
- Add Voice Settings controls for TTS input mode.
- Add i18n keys for the new preview buttons and setting labels.
- Merge latest main and preserve newer FilesView toolbar/editor changes.

Validation:
- bun test packages/ui/src/stores/useConfigStore.test.ts packages/ui/src/components/chat/message/parts/ToolPart.test.ts packages/web/server/lib/tts/routes.test.js
- bun run type-check
- bun run lint
- git diff --check

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/hooks/useMessageTTS.ts

@@ -35,6 +35,7 @@ export function useMessageTTS(): UseMessageTTSReturn {
     const openaiCompatibleUrl = useConfigStore((state) => state.openaiCompatibleUrl);
     const openaiCompatibleTtsModel = useConfigStore((state) => state.openaiCompatibleTtsModel);
     const showMessageTTSButtons = useConfigStore((state) => state.showMessageTTSButtons);
+    const ttsInputMode = useConfigStore((state) => state.ttsInputMode);
 
     const isServerProvider = voiceProvider === 'openai' || voiceProvider === 'openai-compatible';
     const shouldCheckOpenAIAvailability = showMessageTTSButtons && isServerProvider;
@@ -64,7 +65,9 @@ export function useMessageTTS(): UseMessageTTSReturn {
         setIsPlaying(true);
         
         try {
-            const textToSpeak = sanitizeForTTS(text);
+            const shouldUseRaw = ttsInputMode === 'raw' && isServerProvider;
+            const sanitizedText = sanitizeForTTS(text);
+            const textToSpeak = shouldUseRaw ? text : sanitizedText;
             
             if (isServerProvider && isServerTTSAvailable) {
                 const voice = voiceProvider === 'openai-compatible' ? openaiCompatibleVoice : openaiVoice;
@@ -83,7 +86,7 @@ export function useMessageTTS(): UseMessageTTSReturn {
                 });
             } else if (voiceProvider === 'say' && isSayTTSAvailable) {
                 const wordsPerMinute = Math.round(100 + (speechRate - 0.5) * 200);
-                await speakSayTTS(textToSpeak, {
+                await speakSayTTS(sanitizedText, {
                     voice: sayVoice,
                     rate: wordsPerMinute,
                     onEnd: () => setIsPlaying(false),
@@ -94,7 +97,7 @@ export function useMessageTTS(): UseMessageTTSReturn {
                 await browserVoiceService.waitForVoices();
                 await browserVoiceService.resumeAudioContext();
                 await browserVoiceService.speakText(
-                    textToSpeak,
+                    sanitizedText,
                     navigator.language || 'en-US',
                     () => setIsPlaying(false),
                     {
@@ -123,6 +126,7 @@ export function useMessageTTS(): UseMessageTTSReturn {
         openaiCompatibleTtsModel,
         isServerTTSAvailable,
         isSayTTSAvailable,
+        ttsInputMode,
         speakServerTTS,
         speakSayTTS,
         stop,