chore(tooling): migrate lint and formatting to oxlint and oxfmt (tldraw#8258)

Closes tldraw#7572.

In order to remove slow dual-linting and simplify the toolchain, this PR
fully migrates the repo from ESLint + Prettier to Oxlint + Oxfmt, with
workspace lint scripts executing Oxlint from the repo root for
consistent config resolution.

This removes the ESLint config and in-repo ESLint plugin setup, adds an
Oxlint JS plugin for tldraw-specific rules, switches formatter commands
and config to Oxfmt, and updates package/workspace scripts and CI to use
the new stack end-to-end.

### After:
Oxlint: ~6s
Oxfmt: ~162ms

### Before:
Eslint: ~1min 15s
Prettier: ~4s

### Change type

- [x] `improvement`

### Test plan

1. Run `yarn lint` from repo root.
2. Run `yarn lint` from a workspace (for example `packages/tldraw` and
`apps/dotcom/client`) and verify it passes.
3. Run `yarn check-packages` and verify lint script expectations pass.
4. Run `yarn format-current` and `yarn lint-current` on changed files.

- [ ] Unit tests
- [ ] End to end tests

Author: mimecuvalo

.github/workflows/checks.yml

@@ -15,20 +15,6 @@ defaults:
     shell: bash
 
 jobs:
-  lint:
-    name: 'Lint'
-    timeout-minutes: 15
-    runs-on: ubuntu-latest-16-cores-arm-open
-
-    steps:
-      - name: Check out code
-        uses: actions/checkout@v6
-
-      - uses: ./.github/actions/setup
-
-      - name: Lint
-        run: yarn lint
-
   test:
     name: 'Tests & checks'
     timeout-minutes: 15
@@ -58,13 +44,11 @@ jobs:
           path: |
             .lazy
             **/.lazy
-            .eslintcache
             **/.tsbuild
             **/*.tsbuildinfo
-            node_modules/.cache/prettier
-          key: test-tools-${{ runner.os }}-${{ hashFiles('yarn.lock', 'eslint.config.mjs', 'lazy.config.ts') }}-${{ github.sha }}
+          key: test-tools-${{ runner.os }}-${{ hashFiles('yarn.lock', '.oxlintrc.json', '.oxfmtrc.json', 'lazy.config.ts') }}-${{ github.sha }}
           restore-keys: |
-            test-tools-${{ runner.os }}-${{ hashFiles('yarn.lock', 'eslint.config.mjs', 'lazy.config.ts') }}-
+            test-tools-${{ runner.os }}-${{ hashFiles('yarn.lock', '.oxlintrc.json', '.oxfmtrc.json', 'lazy.config.ts') }}-
 
       - name: Typecheck
         run: yarn build-types
@@ -80,6 +64,9 @@ jobs:
       - name: Check API declarations and docs work as intended
         run: yarn api-check
 
+      - name: Lint
+        run: yarn lint
+
       - name: Check dotcom localizations
         run: |
           yarn build-i18n 

.oxfmtrc.json

@@ -0,0 +1,10 @@
+{
+	"$schema": "./node_modules/oxfmt/configuration_schema.json",
+	"trailingComma": "es5",
+	"singleQuote": true,
+	"semi": false,
+	"printWidth": 100,
+	"tabWidth": 2,
+	"useTabs": true,
+	"sortPackageJson": false
+}