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/components/sections/openchamber/VoiceSettings.tsx

@@ -161,6 +161,8 @@ export const VoiceSettings: React.FC = () => {
     const openaiCompatibleTtsModel = useConfigStore((state) => state.openaiCompatibleTtsModel);
     const setOpenaiCompatibleTtsModel = useConfigStore((state) => state.setOpenaiCompatibleTtsModel);
     const showMessageTTSButtons = useConfigStore((state) => state.showMessageTTSButtons);
+    const ttsInputMode = useConfigStore((state) => state.ttsInputMode);
+    const setTtsInputMode = useConfigStore((state) => state.setTtsInputMode);
     // STT settings
     const sttProvider = useConfigStore((state) => state.sttProvider);
     const setSttProvider = useConfigStore((state) => state.setSttProvider);
@@ -1053,6 +1055,36 @@ export const VoiceSettings: React.FC = () => {
                         <span className="typography-ui-label text-foreground">{t('settings.voice.page.field.messageReadAloudButton')}</span>
                     </div>
 
+                    <div className="pb-1.5 pt-0.5">
+                        <div className="flex min-w-0 flex-col gap-1.5">
+                            <div className="flex items-center gap-1.5">
+                                <span className="typography-ui-label text-foreground">
+                                    {t('settings.voice.page.field.ttsInputMode')}
+                                </span>
+                            </div>
+                            <div className="flex flex-wrap items-center gap-1">
+                                <Button
+                                    variant="chip"
+                                    size="xs"
+                                    aria-pressed={ttsInputMode === 'sanitized'}
+                                    onClick={() => setTtsInputMode('sanitized')}
+                                    className="!font-normal"
+                                >
+                                    {t('settings.voice.page.field.ttsInputModeSanitized')}
+                                </Button>
+                                <Button
+                                    variant="chip"
+                                    size="xs"
+                                    aria-pressed={ttsInputMode === 'raw'}
+                                    onClick={() => setTtsInputMode('raw')}
+                                    className="!font-normal"
+                                >
+                                    {t('settings.voice.page.field.ttsInputModeRaw')}
+                                </Button>
+                            </div>
+                        </div>
+                    </div>
+
                 </section>
 
                 {voiceModeEnabled && isSupported && (