build: Android's built-in Kotlin, the three plugins applying KGP themselves patched in third_party/

AGP 9 compiles Kotlin itself (android.builtInKotlin=true in every app),
and warns that applying the Kotlin Gradle Plugin will soon fail.
flutter_web_auth_2 5.1.0, keyboard_height_plugin 0.3.0 and flutter_tts
4.2.5 still apply it unconditionally, so their pub releases are copied
into third_party/ with only their android/build.gradle changed, and
the root overrides them by path (third_party/README.md says when to
drop each). The servers' images copy third_party/, as pub refuses an
override whose path is missing. third_party/ isn't our own code: left
out of the analysis and the format check.

All four apps' APKs build without the warning. A Kotlin daemon's
session file that slipped into Train's android/ goes, and every app's
android/.gitignore keeps .kotlin/ out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

third_party/keyboard_height_plugin/CHANGELOG.md

@@ -0,0 +1,67 @@
+## 0.3.0
+
+### iOS Updates
+* Add Swift Package Manager support (fixes #17)
+  * Flutter 3.44+ will default to SwiftPM; CocoaPods support is retained for backward compatibility
+  * Added `Package.swift` manifest at `ios/keyboard_height_plugin/`
+  * Source files are symlinked so both CocoaPods and SwiftPM resolve the same code
+
+## 0.2.0
+
+**BREAKING CHANGES:**
+This version requires modern Android build tooling. For projects using older versions, please continue using version 0.1.5.
+
+### Requirements
+- Android Gradle Plugin 8.6.0+
+- Gradle 8.7+
+- Kotlin 2.1.0+
+- Java 17+
+
+### Android Updates
+* **BREAKING:** Update compileSdkVersion from 31 to 34 (fixes #14)
+* **BREAKING:** Update Android Gradle Plugin from 7.2.0 to 8.6.0
+* **BREAKING:** Update Kotlin from 1.7.10 to 2.1.0
+* **BREAKING:** Migrate to declarative Gradle plugin system (Gradle 8.x requirement)
+* Add namespace declaration for AGP 8.6+ compatibility
+* minSdkVersion remains 16 (Android 4.1+) - no change to device compatibility
+
+### iOS Updates
+* Add Privacy Manifest (PrivacyInfo.xcprivacy) required for App Store submissions (fixes #6)
+* Fix example app Podfile configuration to eliminate RunnerTests errors
+
+### Infrastructure
+* Add comprehensive CI/CD pipeline with GitHub Actions
+* Add automated testing for code analysis, formatting, and builds
+* Add PR template with testing checklist
+* Add TESTING.md documentation
+* Update example app .gitignore for Flutter-generated files
+
+### Migration Guide
+If you need to upgrade from 0.1.5:
+1. Update your project to use AGP 8.6+, Gradle 8.7+, Kotlin 2.1+, and Java 17+
+2. Follow the Flutter AGP migration guide: https://docs.flutter.dev/release/breaking-changes/flutter-gradle-plugin-apply
+
+If your project cannot upgrade these dependencies yet, remain on version 0.1.5.
+
+## 0.0.1
+
+* Initial release.
+
+## 0.0.2
+
+* Documentation.
+
+## 0.0.3
+
+* More documentation.
+
+## 0.0.4
+
+* N/A
+
+## 0.0.5
+
+* Support for AGP 8.0.0
+
+## 0.1.5
+* Merge in fix for incorrect height when navigation bar is not visible. https://github.com/nschairer/keyboard_height_plugin/pull/8/files