fix: harden Anland direct-surface pipeline

[wyyyz1937365497]

Summary

• select the actual writable Surface dma-buf and preserve acquire/render fence ownership
• serialize complete consumer data-channel frames without holding state across blocking sends
• make fallback shutdown blocked writers before descriptor close/reuse
• bind variable-length output payloads to their originating connection generation
• keep active dma-buf republishing active and restore/reannounce audio after reconnect
• run service resource callbacks outside internal locks with generation-checked commit
• supervise the KWin/Plasma session with stale Wayland-socket protection
• complete Android key mapping and document the updated consumer contracts

Verification

• final Android plain debug APK builds successfully with JDK 17
• host regression passed active republish plus 4,000 input and 4,000 dma-buf frames concurrently
• reconnect regression proves a stale clipboard drain cannot consume the new-generation stream
• blocked-writer regression proves fallback interrupts an undrained data socket without deadlock
• the pre-amend direct-surface build was installed and cold-started on the target device
• a controlled producer restart completed fallback and reconnect without killing the consumer
• direct input was manually verified on-device

The final audio/payload/deadlock amendments were build- and host-regression-verified only; no additional device experiment was run per request.