Context

Phase 5 Community Detection (epic #1222, issue #1228) loads all entities and edges into memory before building a petgraph graph for label propagation.

Problem

detect_communities calls store.all_entities() and all_active_edges_stream().try_collect(), fully materializing both tables into Vecs. At >5K entities, memory usage grows unbounded. Peak heap includes: entities Vec + edges Vec + edge_facts_map (cloned facts) + petgraph adjacency structures.

Suggested Fix

Add a hard cap check before loading: if entity_count() > COMMUNITY_DETECTION_MAX (e.g., 10K), skip community detection and log a warning. Alternatively, build the petgraph incrementally from the stream without collecting.

Source

PERF-01 from Phase 5 performance analysis.