New Features:
- find_references: Find all references to a symbol
- find_callers: Find all callers of a function
- find_implementations: Find types implementing interfaces

Database:
- Schema v3 with symbol_refs and type_relations tables
- Automatic migration from v2 → v3

Performance:
- ~20-25% token reduction for navigation workflows
- 1 tool call vs 4-8 for 'who calls X?' queries
- <1 second vs 30+ seconds response time

Implementation:
- AST-based reference extraction (Go + TypeScript)
- 8,662 references extracted from codetect codebase
- 9 unit tests passing
- 25 eval test cases included