Restore PlayerScreen focus ownership

[rovkinmax]

Summary

• Restore deterministic focus ownership between the player anchor, controls, and settings panels.
• Restore focus after panel/controls Back actions and reopen controls on supported D-pad/media input.
• Add focused JVM and Android instrumentation regression coverage.

Compliance Review

PASS (August 31, 2026). The reviewed changes remain within PUB-80 scope; no compliance findings, playback/network/domain behavior changes, dependency changes, generated changes, or unrelated source changes were found.

Verification

• Focused player JVM suite: 137/137 passed.
• Detekt: 111 immutable baseline findings, with no task-introduced differential.
• :app:compileDevDebugKotlin, :app:compileInstrumentationDebugAndroidTestKotlin, and both instrumentation assemblies passed with reruns.
• Focused Android instrumentation tests (PlayerScreenContentFocusTest and PlayerVideoSurfaceTest): 18/18 passed on emulator-5556.
• git diff --check passed.
• Runtime Smoke sequence 44 passed the authorized mixed real-player path on emulator-5556: one bounded Resume, panel Back restoration, controls-to-player Back, and D-pad reopening. The app was stopped, evidence audit scanned 0 files, and the emulator lease was released.

Known skipped checks

• Runtime lifecycle round-trip and second-Back replay were not repeated because the August 31, 2026 authorization permits only one Resume and its unavoidable saved position; deterministic focused tests retain those proofs.

No same-repository source issue URL is attached to PUB-80, so no closing reference is included.