[None][docs] define Python native KV transfer ownership contract

[chienchunhung]

Summary

• document the Python-native KV-transfer lifetime gaps remaining after [TRTLLM-13614][feat] Disaggregated KV-cache bounce transfer #15618 and the partial overlap with [TRTLLM-13614][fix] Enhance the dis-agg bounce buffer workflow #16116
• define a registry-owned endpoint lifecycle record spanning KV and bounce leases, asynchronous CUDA/NIXL work, identity/replay, cancellation, and shutdown
• scope a phased implementation, rollout/configuration gates, deterministic fault tests, and expected performance/capacity impact

Scope

This targets Python-native KvCacheTransceiverV2 direct, bounce, and fallback paths. The separate C++ CacheTransceiver is a non-goal; small KV-manager or NIXL binding changes may still be required to enforce leases and expose definitive quiescence.

Validation

• completed iterative trtllm-review self-review passes through a final clean pass covering lifecycle/protocol correctness, documentation/scope, and performance/capacity
• pre-commit run --files docs/design/README.md docs/design/disagg-kv-transfer-ownership/README.md docs/design/disagg-kv-transfer-ownership/implementation-plan.md
• git diff --check 54d484fd3

Documentation only; no runtime or GPU tests were required.

[chienchunhung]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #59129 [ run ] triggered by Bot. Commit: b9ff215 Link to invocation

[tensorrt-cicd]

PR_Github #59129 [ run ] completed with state SUCCESS. Commit: b9ff215
/LLM/main/L0_MergeRequest_PR pipeline #47639 completed with status: 'SUCCESS'

CI Report

Link to invocation