Add AST extraction tests, broader ignore patterns, build dist

- ast-extract.ts: Support tree-sitter-python and tree-sitter-go grammar
  loading (pkg.language fallback)
- discover.ts: Add cache directories to default ignore (.cache, tmp,
  temp, .turbo, .parcel-cache, .eslintcache, .prettiercache)
- tests: Add TypeScript AST extraction tests (exports + imports)
- Verified on real project: media_library_viewer (196 .pi-map.md files)
  with accurate React component extraction
- Build: npm run build produces clean dist/ output

All 16 tests pass.

package-lock.json

@@ -11,6 +11,8 @@
       "dependencies": {
         "ignore": "^5.3.0",
         "tree-sitter": "^0.21.0",
+        "tree-sitter-go": "^0.25.0",
+        "tree-sitter-python": "^0.25.0",
         "tree-sitter-typescript": "^0.21.0"
       },
       "bin": {
@@ -3318,6 +3320,44 @@
         "node-gyp-build": "^4.8.0"
       }
     },
+    "node_modules/tree-sitter-go": {
+      "version": "0.25.0",
+      "resolved": "https://registry.npmjs.org/tree-sitter-go/-/tree-sitter-go-0.25.0.tgz",
+      "integrity": "sha512-APBc/Dq3xz/e35Xpkhb1blu5UgW+2E3RyGWawZSCNcbGwa7jhSQPS8KsUupuzBla8PCo8+lz9W/JDJjmfRa2tw==",
+      "hasInstallScript": true,
+      "license": "MIT",
+      "dependencies": {
+        "node-addon-api": "^8.3.1",
+        "node-gyp-build": "^4.8.4"
+      },
+      "peerDependencies": {
+        "tree-sitter": "^0.25.0"
+      },
+      "peerDependenciesMeta": {
+        "tree-sitter": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/tree-sitter-python": {
+      "version": "0.25.0",
+      "resolved": "https://registry.npmjs.org/tree-sitter-python/-/tree-sitter-python-0.25.0.tgz",
+      "integrity": "sha512-eCmJx6zQa35GxaCtQD+wXHOhYqBxEL+bp71W/s3fcDMu06MrtzkVXR437dRrCrbrDbyLuUDJpAgycs7ncngLXw==",
+      "hasInstallScript": true,
+      "license": "MIT",
+      "dependencies": {
+        "node-addon-api": "^8.5.0",
+        "node-gyp-build": "^4.8.4"
+      },
+      "peerDependencies": {
+        "tree-sitter": "^0.25.0"
+      },
+      "peerDependenciesMeta": {
+        "tree-sitter": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/tree-sitter-typescript": {
       "version": "0.21.2",
       "resolved": "https://registry.npmjs.org/tree-sitter-typescript/-/tree-sitter-typescript-0.21.2.tgz",