Fix skip last calculation at increased playback speeds

[sztomek]

Description

Skip Last was not accounting for playback speed: the trigger compared media-time remaining against the configured skipLastSecs, so a user playing at 2x with Skip Last set to 2:00 only saved ~1:00 of listening time before the episode auto-skipped. This was reported via Zendesk #11111728 and confirmed by the reporter's own investigation at 2x speed.
This branch extracts two pure helpers (effectiveSkipLastMs and shouldSkipLast) on PlaybackManager's companion object and multiplies the threshold by the current playbackSpeed, so the setting now represents listening time regardless of speed. Sub-1x speeds are clamped to 1x so slow-playback users never get a shorter skip window than they configured, and the log line now includes playbackSpeed to make future support tickets easier to diagnose.
At 1.0x the behaviour is identical to before, so users who don't change speed see no change. New unit tests lock in the 1x baseline, verify the 2x trigger at the correct listening-time threshold, cover the sub-1x guard, and guard the null/zero edge cases.

Fixes PCDROID-542 https://linear.app/a8c/issue/PCDROID-542/skip-last-fires-too-early-at-higher-playback-speeds-skipping-less

Testing Instructions

1. Install the debug build on a device 2. Subscribe to any podcast with episodes longer than ~10 minutes
2. Open the podcast settings and set Skip Last to 2:00.
3. Open the global playback effects and set Playback speed to 2.0x. 5. Play an episode and seek to near the end; confirm the auto-skip fires when the player's displayed remaining time reads ~2:00 (previously it fired at ~1:00). A "Skipped last 2 minutes" toast should appear.
4. Change the playback speed to 1.0x and repeat — Skip Last should fire at ~2:00 remaining (unchanged behaviour).
5. Change the playback speed to 0.8x and repeat — Skip Last should still fire at ~2:00 remaining, never earlier (sub-1x guard).
6. Set Skip Last to 0 (off) and confirm the episode plays to its natural end with no auto-skip, at any playback speed.

Checklist

• If this is a user-facing change, I have added an entry in CHANGELOG.md
• Ensure the linter passes (./gradlew spotlessApply to automatically apply formatting/linting)
• I have considered whether it makes sense to add tests for my changes
• All strings that need to be localized are in modules/services/localization/src/main/res/values/strings.xml
• Any jetpack compose components I added or changed are covered by compose previews
• I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[Copilot]

Pull request overview

Fixes Skip Last triggering too early at higher playback speeds by making the skip threshold represent listening time rather than media time, and adds unit tests to lock in the corrected behavior.

Changes:

• Added pure helper functions (effectiveSkipLastMs, shouldSkipLast) to compute Skip Last thresholds using playback speed (clamping sub-1x to 1x).
• Updated the Skip Last trigger logic to use the helper and included playback speed in the diagnostic log line.
• Added unit tests covering 1x baseline, >1x scaling, sub-1x clamping, and edge cases (null/zero config, invalid duration/position).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
modules/services/repositories/src/main/java/au/com/shiftyjelly/pocketcasts/repositories/playback/PlaybackManager.kt	Introduces helper-based Skip Last thresholding that scales with playback speed and updates the runtime skip check/logging.
modules/services/repositories/src/test/java/au/com/shiftyjelly/pocketcasts/repositories/playback/PlaybackManagerSkipLastTest.kt	Adds unit tests verifying speed-scaled Skip Last behavior and key edge cases.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

[wpmobilebot]

Version 8.11 has now entered code-freeze, so the milestone of this PR has been updated to 8.12.

[geekygecko]

@sztomek would you mind looking at the comments above?

[sztomek]

@geekygecko addressed the comments

[wpmobilebot]

Version 8.12 has now entered code-freeze, so the milestone of this PR has been updated to 8.13.

[sztomek]

@geekygecko no pressure, but did you have a chance to review the code?

[geekygecko]

Thanks for addressing the comments, I will take a look today.