chore(deps): bump neo4j-graphrag from 1.17.0 to 1.18.0 in /backend/fastapi

[dependabot]

Bumps neo4j-graphrag from 1.17.0 to 1.18.0.

Release notes

Sourced from neo4j-graphrag's releases.

1.18.0

What's Changed

• Guide LLM to define each relationship type once by @​NathalieCharbel in neo4j/neo4j-graphrag-python#537
• Auto-reconcile duplicate relationship types in LLM-generated schemas by @​NathalieCharbel in neo4j/neo4j-graphrag-python#536
• Forbid KEY and EXISTENCE constraints on the same properties by @​adamnsch in neo4j/neo4j-graphrag-python#546

Full Changelog: neo4j/neo4j-graphrag-python@1.17.0...1.18.0

Changelog

Sourced from neo4j-graphrag's changelog.

1.18.0

Changed

• Experimental: GraphSchema validation now rejects KEY and EXISTENCE constraints on the same node or relationship property (including composite KEY members), since KEY already implies mandatory presence. Legacy PropertyType.required migration no longer adds redundant EXISTENCE constraints for KEY-covered properties. The schema-from-text extraction prompt includes the same rule.
• Experimental: the schema-from-text extraction prompt now instructs the LLM to define each relationship type once and reuse it across patterns, using distinct type names only when patterns genuinely need different properties or constraints.
• Experimental: LLM-auto-generated schemas now reconcile duplicate relationship_types (entries sharing the same label) by merging them into a single type that carries the union of their properties, emitting a warning log. This reflects that Neo4j relationship types are global per name.
• Experimental (breaking): GraphSchema now raises SchemaValidationError when the same label appears more than once in relationship_types. Because Neo4j relationship types are global per name (every relationship of a given type shares the same properties and constraints regardless of its endpoints), a label cannot have two conflicting definitions.

Commits

• 4aa918a Bump version to 1.18.0
• eae3255 Forbid KEY and EXISTENCE on the same properties (#546)
• 90147de Revert "Add explain models"
• f728643 Add explain models
• 35ff071 Auto-reconcile duplicate relationship types in LLM-generated schemas (#536)
• 1485eff Guide LLM to define each relationship type once (#537)
• See full diff in compare view

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