chore: add prettier and format all files

- Install prettier ^3.6.2
- Add .prettierrc with project formatting rules
- Add .prettierignore to exclude generated files and dependencies
- Add npm scripts: format and format:check
- Format all files with prettier

package-lock.json

@@ -14,6 +14,7 @@
       "devDependencies": {
         "markdownlint-cli": "^0.46.0",
         "nodemon": "^3.0.1",
+        "prettier": "^3.6.2",
         "tree-sitter-cli": "^0.25.0"
       }
     },
@@ -1278,6 +1279,22 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/prettier": {
+      "version": "3.6.2",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-3.6.2.tgz",
+      "integrity": "sha512-I7AIg5boAr5R0FFtJ6rCfD+LFsWHp81dolrFD8S79U9tb8Az2nGrJncnMSnys+bpQJfRUzqs9hnA81OAA3hCuQ==",
+      "dev": true,
+      "license": "MIT",
+      "bin": {
+        "prettier": "bin/prettier.cjs"
+      },
+      "engines": {
+        "node": ">=14"
+      },
+      "funding": {
+        "url": "https://github.com/prettier/prettier?sponsor=1"
+      }
+    },
     "node_modules/pstree.remy": {
       "version": "1.1.8",
       "resolved": "https://registry.npmjs.org/pstree.remy/-/pstree.remy-1.1.8.tgz",