feat: add Lua and Luau language support (#273)

Adds Lua (.lua) and Luau (.luau) extraction — functions, methods with receivers, type aliases (Luau), require imports (incl. Roblox instance-path), and call edges. Vendors the ABI-15 Lua and ABI-14 Luau tree-sitter grammars. Addresses #232.

src/extraction/grammars.ts

@@ -35,6 +35,8 @@ const WASM_GRAMMAR_FILES: Record<GrammarLanguage, string> = {
   dart: 'tree-sitter-dart.wasm',
   pascal: 'tree-sitter-pascal.wasm',
   scala: 'tree-sitter-scala.wasm',
+  lua: 'tree-sitter-lua.wasm',
+  luau: 'tree-sitter-luau.wasm',
 };
 
 /**
@@ -78,6 +80,8 @@ export const EXTENSION_MAP: Record<string, Language> = {
   '.fmx': 'pascal',
   '.scala': 'scala',
   '.sc': 'scala',
+  '.lua': 'lua',
+  '.luau': 'luau',
 };
 
 /**
@@ -125,8 +129,12 @@ export async function loadGrammarsForLanguages(languages: Language[]): Promise<v
   for (const lang of toLoad) {
     const wasmFile = WASM_GRAMMAR_FILES[lang];
     try {
-      // Pascal and Scala ship their own WASMs (not in tree-sitter-wasms)
-      const wasmPath = (lang === 'pascal' || lang === 'scala')
+      // Some grammars ship their own WASMs (not in tree-sitter-wasms, or the
+      // tree-sitter-wasms build is too old). Lua: tree-sitter-wasms ships an
+      // ABI-13 build that corrupts the shared WASM heap under web-tree-sitter
+      // 0.25 (drops nested calls/imports on every file after the first); we
+      // vendor the upstream ABI-15 wasm instead.
+      const wasmPath = (lang === 'pascal' || lang === 'scala' || lang === 'lua' || lang === 'luau')
         ? path.join(__dirname, 'wasm', wasmFile)
         : require.resolve(`tree-sitter-wasms/out/${wasmFile}`);
       const language = await WasmLanguage.load(wasmPath);
@@ -291,6 +299,8 @@ export function getLanguageDisplayName(language: Language): string {
     liquid: 'Liquid',
     pascal: 'Pascal / Delphi',
     scala: 'Scala',
+    lua: 'Lua',
+    luau: 'Luau',
     unknown: 'Unknown',
   };
   return names[language] || language;