feat: schema v2 migration, database performance, batch query methods

- Add provenance column on edges for tracking how edges were created
- Add project_metadata table for version/provenance tracking
- Make unresolved_refs file_path/language NOT NULL with defaults
- Add composite indexes for unresolved_refs and edges.provenance
- Update v2 migration to handle all new schema additions
- Record schema version on initialize to prevent re-migration
- Add dynamic prepared statement cache (getDynamicStmt) for varying SQL
- Add batch methods: getNodesByIds, getNodesByKinds, getFileHashMap, getFileSyncMap
- Add project metadata methods: getMetadata, setMetadata, getAllMetadata
- Optimize getStats to use single aggregate query
- Optimize getStaleFiles to use temporary table JOIN
- Add provenance parameter to getOutgoingEdges
- Add intent field to SearchOptions type

src/types.ts

@@ -166,6 +166,9 @@ export interface Edge {
 
   /** Column number where relationship occurs */
   column?: number;
+
+  /** How this edge was created */
+  provenance?: 'tree-sitter' | 'scip' | 'heuristic';
 }
 
 /**
@@ -333,6 +336,9 @@ export interface SearchOptions {
 
   /** Whether search is case-sensitive */
   caseSensitive?: boolean;
+
+  /** Search intent for biasing results */
+  intent?: 'api' | 'general';
 }
 
 /**