feat(stdlib): new modules + eslint/tsconfig migration

- Add array/async/etc. modules and type tests; migrate to eslint flat config
  and composite tsconfig (vitest typecheck enabled).
- Fix PubSub.emit to snapshot listeners before iterating (stable EventEmitter
  semantics; avoids invoking listeners added during the same emit).

core/stdlib/package.json

@@ -39,18 +39,18 @@
     }
   },
   "scripts": {
-    "lint:check": "oxlint -c oxlint.config.ts",
-    "lint:fix": "oxlint -c oxlint.config.ts --fix",
+    "lint:check": "eslint .",
+    "lint:fix": "eslint . --fix",
     "test": "vitest run",
     "dev": "vitest dev",
     "build": "tsdown"
   },
   "devDependencies": {
-    "@robonen/oxlint": "workspace:*",
+    "@robonen/eslint": "workspace:*",
     "@robonen/tsconfig": "workspace:*",
     "@robonen/tsdown": "workspace:*",
-    "@stylistic/eslint-plugin": "catalog:",
-    "oxlint": "catalog:",
-    "tsdown": "catalog:"
+    "eslint": "catalog:",
+    "tsdown": "catalog:",
+    "typescript": "^5.9.3"
   }
 }