Added --fire-and-forget flag to cache_aware_proxy.py for async prefill dispatch.
Results on 6P+2D config:
Await: TTFT=1.48s TPOT=0.066s E2E=5.95s 94% success
FnF: TTFT=5.32s TPOT=0.037s E2E=11.9s 85% success
Fire-and-forget improves TPOT by 44% (pipeline overlap) but degrades
TTFT by 260% (decode internally waits for KV, less efficiently than
proxy-level await) and increases errors from KV race conditions.
Full 4-way ablation summary in analyze_ablations.py.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
