Capture resident KV aliases in recurrent CUDA Graphs

[0z5a]

Incremental review: 0z5a/vllm-rlt#15, based on resident async aliases #95. The upstream diff includes the unmerged parent stack; use the fork PR for this change alone.

Purpose

Enable recurrent-core CUDA Graphs for the resident rectangular-alias path. Each graph entry owns stable depth tables and query-depth storage; replay refreshes the current request mapping and reads the live exit map through canonical-depth attention. Preserve the native graph-pool event ordering and update alias-readable history after submission. Finalized source positions remain immutable.

This is stacked on resident async aliases. Compact Graphs and synchronous alias Graphs remain unsupported.

Test Plan

• Affected CPU alias/async/accounting checks: 29 passed, 12 CUDA skips.
• All 60 finite CUDA arms pass at B1–128/C2B, with mixed depths, cancellation/reuse and mapped-host/H2D routing. The 24 native/alias Graph arms recorded 116 captures, 1,116 replays and zero fallbacks. Outputs/exits match native synchronous and all block credits/state slots return. Frozen source 4adada8 naturally exited 0 on RTX5090/Torch2.12.1+cu130.
• Official Ouro1.4B delayed-policy diagnostic: all 36 arms at B1–128/C2B complete, with exact token sequences. Alias Graph has 143 request exit-sequence differences versus native Graph at B16/B32/B64. Recurrent work and actual batch distributions differ; no speed claim is made. Raw counters and frozen provenance.
• Fixed logical replay at official B16/B32 reproduces native/alias complete request objects and every work counter; serialized comparison has 5,493 bitwise-equal hidden/gate/sample stages. All18 tiny replay arms and12 CUDA text-stop/reuse cases pass.
• Frozen delayed-policy GSM8K100: native Graph63/100, alias Graph62/100, with15 token-sequence and43 exit-sequence differences. No quality-equivalence or speed claim. Full quality results and discordant answers.
• Formal fixed-work and natural-scheduling performance remain pending.

Test Result

Fixed-policy E2E comparison	Native Graph tokens/s	Alias Graph tokens/s	Speedup
Official checkpoint	—	—	Not measured

Implementation and validation scope.