Submit F-Droid fdroiddata inclusion MR

[kwsantiago]

Blocks: none (final step, closes acceptance #2 of #228 via F-Droid)
Blocked by: #243 (mlkit swap), #244 (dep audit), plus a release tag cut after the mlkit removal

Problem

F-Droid inclusion requires a merge request to fdroiddata with a metadata/io.privkey.keep.yml describing the build. This is the second half of acceptance 2 of #228.

Blocked on

• Replacing com.google.mlkit (separate issue), F-Droid cannot build our current release as-is.
• Full dependency audit (separate issue).
• A release tag cut after the mlkit removal.

Proposal

Draft metadata/io.privkey.keep.yml referencing:

• Repo: https://github.com/privkeyio/keep-android
• RepoType: git
• Binaries: published GitHub release APK URL pattern
• Builds: exec Dockerfile.reproducible via docker build, copy APK from /out/app-release.apk
• AutoUpdateMode: Version for tag-based auto-updates
• Fastlane metadata path (fastlane/metadata/android)

File the MR at gitlab.com/fdroid/fdroiddata and iterate with F-Droid reviewers.

Acceptance

• MR merged into fdroiddata main.
• App builds cleanly in F-Droid's build-server environment.
• App appears in F-Droid main repo with RB verification badge.

Closes acceptance 2 of #228 for F-Droid channel.