chore(configs): migrate oxlint→eslint presets, refactor tsconfig

- Replace @robonen/oxlint with @robonen/eslint (composable ESLint flat-config
  presets: base, typescript, vue, vitest, imports, node, stylistic).
- Plugins bundled as deps: typescript-eslint, eslint-plugin-vue,
  @vitest/eslint-plugin, eslint-plugin-import-x, eslint-plugin-n,
  eslint-plugin-unicorn, @stylistic/eslint-plugin.
- @robonen/tsconfig: add base/dom/node/vue configs for composite project refs.

configs/tsconfig/tsconfig.node.json

@@ -0,0 +1,9 @@
+{
+    "$schema": "https://json.schemastore.org/tsconfig",
+    "display": "@robonen node (build/test tooling files)",
+    "extends": "./tsconfig.base.json",
+    "compilerOptions": {
+        "lib": ["ESNext"],
+        "types": ["node"]
+    }
+}