Phase 4 D3 Design: Alloc Gate Shape

docs/analysis/PHASE3_FINALIZATION_SUMMARY.md

@@ -238,14 +238,14 @@ IF mean_gain >= +1.0% AND median_gain >= +0.0%:
 
 **Requirement**: perf validation showing `tiny_alloc_gate_fast` self% ≥ 5%
 
-**Design**: `docs/analysis/PHASE3_D3_ALLOC_GATE_SPECIALIZATION_1_DESIGN.md`
+**Design**: `docs/analysis/PHASE4_D3_ALLOC_GATE_SPECIALIZATION_1_DESIGN.md`
 
 **Strategy**: Specialize alloc gate for fixed MIXED configuration
 - Eliminate dynamic checks
 - Inline hot paths
 - Reduce branch complexity
 
-**ENV**: `HAKMEM_ALLOC_GATE_LEGACY_ONLY=0/1`
+**ENV**: `HAKMEM_ALLOC_GATE_SHAPE=0/1`
 
 **Decision Criteria**:
 - IF perf shows ≥5% self% in alloc gate → Proceed with D3