chore: migrate from yarn+prettier to pnpm+oxc

Replace Yarn 4.12.0 with pnpm 10.33.0 and Prettier with oxfmt+oxlint.
Vercel auto-detects pnpm from pnpm-lock.yaml. CI updated accordingly.

Author: quantizor

.github/workflows/ci.yml

@@ -7,16 +7,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: pnpm/action-setup@v4
+
       - uses: actions/setup-node@v4
         with:
           node-version-file: ".nvmrc"
-          cache: yarn
-
-      - name: Enable Corepack
-        run: corepack enable
+          cache: pnpm
 
       - name: Install dependencies
-        run: yarn install --immutable
+        run: pnpm install --frozen-lockfile
 
       - name: Run tests
-        run: yarn test
+        run: pnpm test

.gitignore

@@ -15,12 +15,8 @@ __diff_output__
 # build
 .next
 next-env.d.ts
+*.tsbuildinfo
 
-# Yarn 3
-.pnp.*
-.yarn/*
-!.yarn/patches
-!.yarn/plugins
-!.yarn/releases
-!.yarn/sdks
-!.yarn/versions
+# agent state
+.claude/
+.playwright-mcp/

.husky/pre-commit

@@ -1,4 +1 @@
-#!/usr/bin/env sh
-. "$(dirname -- "$0")/_/husky.sh"
-
-yarn precommit
+pnpm precommit

.lintstagedrc.js

@@ -1,3 +1,3 @@
 module.exports = {
-  '**/*.{js,jsx,ts,tsx}': ['jest -c .jest.config.js --findRelatedTests --passWithNoTests', 'prettier --write'],
+  '**/*.{js,jsx,ts,tsx}': ['jest -c .jest.config.js --findRelatedTests --passWithNoTests', 'oxfmt', 'oxlint'],
 };

.npmrc

@@ -0,0 +1 @@
+auto-install-peers=true

.oxfmtrc.json

@@ -0,0 +1,24 @@
+{
+  "$schema": "./node_modules/oxfmt/configuration_schema.json",
+  "arrowParens": "avoid",
+  "printWidth": 120,
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "es5",
+  "sortPackageJson": false,
+  "ignorePatterns": [
+    "node_modules",
+    "/.next",
+    "/.yarn",
+    "/public",
+    "*.*",
+    "!*.css",
+    "!*.js",
+    "!*.json",
+    "!*.jsx",
+    "!*.less",
+    "!*.ts",
+    "!*.tsx",
+    "!*.yml"
+  ]
+}

.oxlintrc.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "plugins": ["typescript", "unicorn", "oxc", "react", "nextjs", "jsx-a11y", "import", "promise", "jest"],
+  "categories": {
+    "correctness": "error",
+    "suspicious": "warn"
+  },
+  "rules": {
+    "react/react-in-jsx-scope": "off",
+    "import/no-named-as-default": "off",
+    "import/no-unassigned-import": "off"
+  }
+}