Account for navigation bars in the transcripts UI

[MiSikora]

Description

Currently transcripts UI does not handle edge-to-edge well especially when 3-button navigation is enabled. This fixes that.

Closes PCDROID-240

Testing Instructions

1. Enable 3-button navigation.
2. Open the episode details for an episode with generated transcripts.
3. Tap the transcript banner.
4. Verify that the CTA is not obstructed by the navigation buttons.
5. Play the episode.
6. Navigate to the player.
7. Open the transcript.
8. Verify that the CTA is not obstructed by the navigation buttons.
9. Sign in with a paid account.
10. Open the episode details.
11. Tap the transcript banner.
12. Scroll to the bottom of the transcript.
13. Verify that the last line of the transcript is not obstructed by the navigation buttons.

Screenshots or Screencast

Before	After

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.

I have tested any UI changes...

• with different themes
• with a landscape orientation
• with the device set to have a large display and font size
• for accessibility with TalkBack

[Copilot]

Pull request overview

This PR fixes edge-to-edge display issues in the transcripts UI, specifically addressing content obstruction by 3-button navigation bars.

Changes:

• Added window insets padding to the subscription button in the transcripts paywall
• Added bottom spacing to transcript lines to prevent obstruction by navigation bars
• Updated CHANGELOG.md to document the bug fix

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
TranscriptsPaywall.kt	Added window insets padding to the CTA button to prevent navigation bar obstruction
TranscriptLines.kt	Added spacer item with window insets bottom height to prevent last transcript line from being hidden
CHANGELOG.md	Added entry documenting the navigation bar obstruction fix

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.