feat(query): domain pattern fingerprint & drift engine

[zaebee]

Summary

Implement the Domain Pattern Fingerprint & Drift Engine as specified in docs/specs/2026-06-09-domain-pattern-fingerprint-design.md.

Goal: Quantify how far each domain's actual graph topology drifts from its declared ideal architectural pattern.

Key deliverables

• docs/ontology/patterns.yaml — pattern templates + project domain expectations
• src/cgis/query/fingerprint.py — PatternFingerprint dataclass + FingerprintExtractor
• src/cgis/query/drift.py — DriftScorer + DriftReport
• cgis drift CLI command (exit 1 if any domain critical)
• gen_ideal_graph.py --from-ontology mode

Design

See full spec: docs/specs/2026-06-09-domain-pattern-fingerprint-design.md (PR #138)

Out of scope v1

• Probabilistic inference (fingerprint → domain)
• Cross-language SERVES edges
• UI overlay
• dispatcher pattern (requires refactor(resolver): split ResolverEngine into IndexBuilder + SymbolResolver #115 first)