fix(cli): reject apksigner for Android App Bundles

[Boulea7]

Description

Reject Android App Bundle builds configured with apksigner before Gradle or signing commands run. The CLI keeps jarsigner as its default and uses the same resolved signing tool for validation and dispatch.

Change Type

• Fix
• Feature
• Refactor
• Breaking Change
• Documentation
• Other (CI, chores, etc.)

Rationale / Problems Fixed

apksigner only supports APK files. Passing an AAB to it currently produces a misleading MinSdkVersionException / missing manifest error after the bundle has been built. The new validation explains how to select jarsigner or build an APK instead.

Fixes #8428

Tests or Reproductions

• npm test -- --runTestsByPath test/build.android.spec.ts (5 tests passed)
• npm test --workspace @capacitor/cli (89 tests passed)
• npm run build --workspace @capacitor/cli
• npm run lint

The regression tests cover the rejected AAB/apksigner combination and the valid default AAB, explicit AAB/jarsigner, APK/apksigner, and APK/jarsigner paths. External commands are mocked at the runCommand process boundary. A real Android SDK and keystore signing run was not performed.

Screenshots / Media

Not applicable.

Platforms Affected

• Android
• iOS
• Web

Notes / Comments

SwiftLint was skipped by node-swiftlint because validation ran on Linux; the TypeScript and formatting portions of the official lint command passed.