feat(extraction): add Nix language support with module-system option wiring (#324, #332 via #648 — carries #1084) (#1190)

Carries @TyceHerrman's #1084 as the functional base. Extraction + file wiring (imports/modules lists, callPackage), module-system option-path synthesizer, lexical-scope resolution gates, ABI-15 wasm rebuilt from upstream source. Validated on agenix, nix-darwin, home-manager, and nixpkgs (44,368 files, 3m49s, 1.30M nodes).

Co-authored-by: Tyce Herrman <Tyce.Herrman@pm.me>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/db/queries.ts

@@ -211,6 +211,7 @@ export class QueryBuilder {
     deleteUnresolvedByNode?: SqliteStatement;
     getUnresolvedByName?: SqliteStatement;
     getNodesByName?: SqliteStatement;
+    getNodesByNamePrefix?: SqliteStatement;
     getNodesByQualifiedNameExact?: SqliteStatement;
     getNodesByLowerName?: SqliteStatement;
     getUnresolvedCount?: SqliteStatement;
@@ -890,6 +891,20 @@ export class QueryBuilder {
     return rows.map(rowToNode);
   }
 
+  /**
+   * Nodes whose name starts with `prefix`, by index range scan (a LIKE would
+   * skip idx_nodes_name under SQLite's default case-insensitive LIKE).
+   */
+  getNodesByNamePrefix(prefix: string, limit = 20): Node[] {
+    if (!this.stmts.getNodesByNamePrefix) {
+      this.stmts.getNodesByNamePrefix = this.db.prepare(
+        'SELECT * FROM nodes WHERE name >= ? AND name < ? ORDER BY name LIMIT ?'
+      );
+    }
+    const rows = this.stmts.getNodesByNamePrefix.all(prefix, prefix + '￿', limit) as NodeRow[];
+    return rows.map(rowToNode);
+  }
+
   /**
    * Get nodes by exact qualified name match (uses idx_nodes_qualified_name index)
    */