Release 0.6.1: preserve playback timestamps

[reziarlleh]

Summary

• distinguish deliberate episode activation from ordinary zero-position lifecycle checkpoints
• keep completed episode context visible while fresh playback discovery resolves the successor
• remove unused percentage-based completion heuristics from exact progress domain
• correct R-035 documentation: near-end was an example, not the scope or proven cause
• bump the patch candidate to 0.6.1 / code 21 and update project, playback, testing, roadmap, release and regression docs

Verification

• estDebugUnitTest lintDebug assembleDebug assembleDebugAndroidTest assembleRelease: SUCCESS, 90 suites / 471 tests, lint 0 errors
• exact post-commit �ssembleRelease --rerun-tasks: SUCCESS
• exact APK: 6,703,237 bytes; SHA-256 F6CE7CF4F6751A0DE75DC7A5742C603DC139CB8AA8C931EBB77900272517ADB2
• package/code/name: com.kinogo.atv / 21 /