v0.0.3: Split overlay mode, live translation, and stability fixes (#1)

* fix: eliminate duplicate translations and add sentence-based segmentation

- Remove translateWithContext which caused duplicate translations by
  including context translations in the output when Apple Translation
  didn't preserve newline structure
- Add extractCompleteSentences() that detects sentence boundaries via
  linguistic analysis and creates subtitle entries immediately on
  punctuation (. ! ?) instead of waiting for pause timer
- Simplify handlePartialTextStabilized() to consume remaining liveText
  directly as a fallback for unpunctuated speech
- Remove dead translateWithContext method from TranslationService

* feat: add persistent subtle background to overlay for visibility

Add a very low-opacity background (5% black fill + 8% white border)
to the full overlay area so users can always see where the overlay
is positioned, even when no subtitles are displayed.

* fix: prevent overlay window auto-resize and improve lock state controls

Wrap NSHostingView in NSView container to decouple window size from
content, add lock toggle and reset button in Settings > Display, and
fix click-through behavior so locked overlay passes clicks through
while unlocked overlay allows move/resize but blocks underlying clicks.

* fix: resolve duplicate subtitles, race conditions, and improve scroll tracking

- Fix duplicate subtitle entries caused by recognizer text reformulation:
  find longest common prefix instead of resetting consumed state entirely,
  add deduplication check (last 2 entries within 2s) before adding entries
- Fix race condition in stopCapture: set isCapturing=false before
  stopRecognition to prevent phantom entries from Combine sink
- Fix SystemAudioCapture: finish continuation before awaiting stopCapture
  to prevent dangling yields; remove force-unwrap on re-entry
- Fix SpeechRecognizer: handle partial result + error simultaneously
  to prevent recognition task from silently dying
- Fix scroll tracking: replace unreliable onAppear/onDisappear on
  zero-height view with onScrollGeometryChange for reliable bottom detection
- Fix handlePartialTextStabilized: use stored sink value instead of
  reading speechRecognizer.currentText directly (timing consistency)
- Fix lastConsumedTail: unconditionally clear after first use to prevent
  stale overlap stripping in subsequent recognition sessions
- Fix detectLanguageIfNeeded: check isCapturing before language change
- Fix LanguagePickerView: add defensive guard and correct swap announcement
- Fix MenuBarView: show "Auto" when source language is auto-detect
- Update README with comprehensive setup guide and feature documentation

* feat: add split overlay mode, live translation, and overlay stability fixes

- Add dual display mode (combined/split) with independent recognition and translation windows
- Add live translation that shows translations as text is being recognized
- Fix invisible overlay blocking clicks by setting explicit hosting view frame
- Add screen boundary clamping to prevent overlay windows from appearing off-screen
- Add "Reset All Overlay Windows" button in Settings > Display Mode
- Add duplicate text filtering, punctuation-only entry removal
- Improve auto-scroll to always follow latest text
- Sync lock/unlock state across both overlay windows
- Update README with comprehensive setup guide, usage instructions, and troubleshooting

fix: prevent text loss on speech recognizer restart

Handle empty currentText (recognizer restart) before updating liveText,
so remaining partial text is consumed into subtitle entries before reset.

feat: initial release v0.0.1

Real-time speech recognition and translation overlay for macOS.
Captures system audio via ScreenCaptureKit, transcribes with
SFSpeechRecognizer, translates using Apple Translation framework,
and displays subtitles in a floating overlay window.