RETE hot-path optimizations driven by cluster cProfile evidence Cluster cProfile on combined_40_ings (recipe wall 23.6s on dev, v0.5.419) showed orchestration at 82% of wall time, with these top hot spots: ncalls tottime function 897K 1.23s alpha_network.activate 2.6M 0.74s isinstance 1.76M 0.79s hasattr 974K 0.60s getattr 403K 0.56s alpha_network._get_related_at_depth 1.39M 0.44s _abc_instancecheck (driven by isinstance) This release ships three changes targeting these: 1. _kind/_is_compound flags (8c8923aca) Replace per-callback isinstance + set-membership with class-level bit flags set at network-build time. Eliminates 2.6M isinstance calls on combined_40 → 0 in selective_evaluator hot path. 2. Per-batch BFS walk cache (53fd00f86) Cache RelatedNodeAlpha._get_related_at_depth results within a single on_facts_changed sweep. Measured 91.3% hit rate on two_origins fixture; on combined_40 the BFS cumtime is 2.4s → should drop to ~0.2s. 3. Drop hasattr/getattr probes on alpha hot path (06b932bc7) Hoist condition fields into PerRelatedNodeAlpha.__init__ (frozen dataclass — sound). Drop dead hasattr guards for methods always defined on Node base class. Measured -29.9% hasattr, -21.4% getattr on two_origins; -2.6% wall time. Tests: 503/503 green (orchestrator + benchmark suites). Local two_origins: 3.05-3.20s (within run-to-run noise). Expected cluster gain: 3-5s off the 23.6s combined_40_ings baseline, biggest impact on the 18.6s outside-GFM time (selective_evaluator, relational fan-out, alpha activation). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>