Remove unused batch methods, dynamic stmt cache, and intent field

- Remove getNodesByIds, getNodesByKinds (zero callers)
- Remove getFileHashMap, getFileSyncMap (zero callers)
- Remove getDynamicStmt cache (only used by removed batch methods)
- Revert getStaleFiles to simple implementation (zero callers, no need to optimize)
- Remove intent field from SearchOptions (never read in search logic)

src/types.ts

@@ -336,9 +336,6 @@ export interface SearchOptions {
 
   /** Whether search is case-sensitive */
   caseSensitive?: boolean;
-
-  /** Search intent for biasing results */
-  intent?: 'api' | 'general';
 }
 
 /**