0.12.0 Build 0-kmb.7 — post-minSdk cleanup tail

Five items unlocked by the minSdk 19->26 raise, plus feature/dependency-sweep folded in:

• Merged feature/dependency-sweep (Gradle 9.7.1, AGP 9.3.2, Kotlin 2.2.21, Dagger 2.59.2),
  then re-swept AndroidX to current stable: appcompat 1.8.0, material 1.14.0,
  navigation 2.10.0, lifecycle 2.11.0. compileSdk raised 34->35 (navigation's transitive
  core-ktx requirement); targetSdk unchanged at 34.
• Removed 5 dead SDK_INT >= O (API 26) branches, now always-true.
• Dropped legacy-support-v13/v4/legacy-preference-v14; replaced androidx.legacy.widget.Space.
• Removed obsolete android.enableJetifier=true.
• Bumped constraintlayout 2.1.4 -> 2.2.2.
• Fixed InternalWebClient.dialogUtils: constructor injection instead of never-populated
  @Inject field (live UninitializedPropertyAccessException on any SSL error).

Verified: unit tests (6, CameraFpsPin), assembleProdRelease + lintVital (0 Fatal),
smoke-device.sh, panel-render-probe.sh, manual on-device check of settings/About/MQTT
screens, promote.sh (install, relaunch, post-install render probe — PASS).

See CHANGELOG.md for full detail.