Feat/rsvp expressive reading

[Steadyx]

What changed

Improve RSVP phrasing and pacing, preserve local author emphasis from EPUB/HTML, and keep English-specific language rules scoped to English books.

Shorten cold startup by playing a prepared opening while the chapter loads. Keep words and saved positions aligned during handoff, and make the full chapter available for replay and swiping as soon as it is ready. Also update Kotlin and the Compose compiler to 2.4.21 to resolve the lint failure.

Risk

Changes affect frame timing, source-position alignment, and navigation during startup. Regression tests cover pause/resume, skipped or repeated words, chapter endings, and navigation outside the opening buffer.

Validation

Local full qualityGate passed, including lint and all 914 unit tests. All 18 device tests passed on CPH2493 / Android 16; committed snapshot checks and Git hooks also passed.

• ./gradlew qualityCheck
• ./gradlew qualityGate when Android/UI/build behavior changed
• Android Lint attempted for Android-facing changes; any analyzer stall is documented separately
• Focused regression tests added or updated
• git diff --check
• Connected instrumentation run when device behavior changed, or the missing device/emulator is documented

Quality policy

• No baseline, ignoreFailures, broad exclusion, or unrelated threshold relaxation was added
• Any new suppression is declaration-scoped and explained next to the annotation
• No generated files, debug logging, commented-out code, or unrelated formatting churn is included