GPU Allocation Fallback

Send typed results to POST /api/agent/gpu-allocation/attempt with a stable logical_allocation, the requested compatibility/execution/disk invariants, typed failure evidence, and the identical compatible preemptible candidate. The grounded route uses zero model tokens.

Only quota/capacity exhaustion, insufficient GPU or Unschedulable, and no compatible product/affinity count. Auth, RBAC, network, image-pull, checkpoint, application, runtime, cancellation, and timeout failures never count. The default prompt occurs on the third qualifying failure, or immediately when deterministic preflight proves on-demand cannot succeed and compatible preemptible capacity is available.

Never switch automatically. Present the returned question and proposed action. Accept through POST /api/agent/gpu-allocation/consent with its single-use, action-digest-bound confirm_token; decline with accept: false. A decline keeps on-demand and suppresses the same evidence until materially new evidence arrives.

Preserve GPU family/product/count, image/digest, SM and RT-core requirements, backend, model, workload tier, execution mode, and boot-disk count/bytes. The state record contains only redacted digests, classification, selected pool, and consent outcome. Success or a changed logical allocation resets attempt state.

Verify changes with:

npa/.venv/bin/python -m pytest \
  npa/tests/cli/test_agent_gpu_allocation_fallback.py \
  npa/tests/cli/test_agent_backend_render.py -q