Module conflict 

APEX-MEM conflict resolution for cardinality-1 predicates.

When multiple head edges share (subject, canonical_relation) and the predicate has cardinality = 1, this module selects one authoritative edge per the configured ConflictStrategy:

• Recency: picks the edge with the greatest valid_from.
• Confidence: picks the edge with the highest confidence.
• Llm: delegates to an LLM provider with a 500 ms hard timeout, falling back to Recency.

Invariants

• The resolver is only invoked for cardinality-1 predicates; cardinality-n predicates pass all head edges through unchanged.
• The LLM strategy respects a 500 ms mandatory timeout and a per-turn budget cap; both exhaustion paths fall back to Recency.
• Losing edges are optionally retained in alternatives (disabled by default).

Unique index vs conflict resolver

The partial unique index uq_graph_edges_active_head prevents same-target duplicates for a cardinality-1 predicate (i.e., two rows for the exact same target entity cannot both be active). The conflict resolver handles the orthogonal case: two head edges with different targets for the same cardinality-1 predicate (e.g., works_at Acme vs works_at Globex).

Structs

ApexMetrics

Atomic counters for APEX-MEM Prometheus metrics.

ConflictResolver

Conflict resolver for cardinality-1 predicate groups.

ConflictResult

Output of conflict resolution for a single (subject, canonical_relation) group.

Enums

ConflictStrategy

Conflict resolution strategy for cardinality-1 predicates.

Constants

SUPERSEDE_DEPTH_CAP

Maximum allowed depth when walking a supersedes chain for cycle detection. Defined here as a named constant per critic nit #7.