Add number normalization and enhance UI for voice preview

- Implemented number conversion to words for grouped numbers in text normalization.
- Added configuration options for number conversion in ApostropheConfig.
- Updated the normalize_apostrophes function to include number normalization.
- Enhanced the dashboard UI with new sections for manuscript and narrator defaults.
- Improved voice preview functionality with better handling of audio playback and status updates.
- Refactored HTML templates for cleaner structure and added new fields for speaker settings.
- Updated CSS styles for improved layout and responsiveness.
- Added tests to ensure correct spelling of grouped numbers in the normalization process.
- Included num2words as a new dependency in pyproject.toml.

tests/test_text_normalization.py

@@ -63,3 +63,8 @@ def test_normalize_roman_titles_preserves_separators() -> None:
     assert normalized[0] == "  4.  The Trial"
     assert normalized[1] == "5 - The Verdict"
     assert normalized[2].startswith("6\nAftermath")
+
+
+def test_grouped_numbers_are_spelled_out() -> None:
+    normalized = _normalize_for_pipeline("The vault holds 35,000 credits")
+    assert "thirty-five thousand" in normalized.lower()