feat: Add auto-prefix option for chapter titles and enhance reader functionality

- Introduced `auto_prefix_chapter_titles` setting in Job and PendingJob classes to control prefixing of chapter titles with "Chapter".
- Updated job detail and settings templates to display and configure the new option.
- Enhanced reader.js to manage playback controls, including chapter navigation and playback speed adjustments.
- Implemented a new prepare_chapters.html template for chapter selection and configuration during job preparation.
- Added tests for chapter title formatting and heading equivalence to ensure correct behavior of the new feature.

tests/test_conversion_chapter_titles.py

@@ -0,0 +1,27 @@
+from abogen.web.conversion_runner import (
+    _format_spoken_chapter_title,
+    _headings_equivalent,
+    _strip_duplicate_heading_line,
+)
+
+
+def test_format_spoken_chapter_title_adds_prefix() -> None:
+    assert _format_spoken_chapter_title("1: A Tale", 1, True) == "Chapter 1: A Tale"
+
+
+def test_format_spoken_chapter_title_respects_existing_prefix() -> None:
+    assert _format_spoken_chapter_title("Chapter 2: Story", 2, True) == "Chapter 2: Story"
+
+
+def test_format_spoken_chapter_title_handles_empty_title() -> None:
+    assert _format_spoken_chapter_title("", 4, True) == "Chapter 4"
+
+
+def test_headings_equivalent_ignores_case_and_prefix() -> None:
+    assert _headings_equivalent("1: The House", "Chapter 1: The House")
+
+
+def test_strip_duplicate_heading_line_removes_first_match() -> None:
+    text, removed = _strip_duplicate_heading_line("Chapter 3: Intro\nBody text", "Chapter 3: Intro")
+    assert removed is True
+    assert text.strip() == "Body text"