[skip chg] Migrate linting and formatting to oxc

[timotheeguerin]

Replaces ESLint with oxlint (+ oxlint-tsgolint for type-aware linting) and Prettier with oxfmt.

Linting (ESLint → oxlint)

• New .oxlintrc.json mirroring the previous ESLint config (same custom rules, ignores, trace-cli no-console override, and the vitest test-file rules).
• Type-aware linting is enabled via --type-aware, but scoped to only no-floating-promises to preserve the previous behavior; all other type-aware rules are disabled (see comments in the config for how to opt back in).
• packages/devtools migrated to oxlint using the react-hooks plugin.
• Removed all ESLint dependencies and eslint.config.js files.

Formatting (Prettier → oxfmt)

• New .oxfmtrc.json (printWidth: 80, sortImports, sortPackageJson: false), with the Prettier ignore patterns migrated over.
• Removed prettier / prettier-plugin-organize-imports.
• The bulk reformat is isolated in its own commit (style: apply oxfmt formatting). Main visible changes: ternaries revert from experimentalTernaries to the standard style, and imports are grouped via sortImports.

Other

• Updated the pnpm catalog, root scripts, and VSCode settings/extensions (oxc.oxc-vscode).
• Added @types/node at the root so type-aware linting can resolve types: ["node"].
• Removed one unreachable return surfaced by oxlint (csharp symbols).

Verified

build, lint (root + devtools), format:check, and sync-publish-config:check all pass.

[github-actions]

❌ There is undocummented changes. Run chronus add to add a changeset or click here.

The following packages have changes but are not documented.

• ❌@alloy-js/babel-plugin
• ❌@alloy-js/cli
• ❌@alloy-js/core
• ❌@alloy-js/create
• ❌@alloy-js/csharp
• ❌@alloy-js/go
• ❌@alloy-js/java
• ❌@alloy-js/json
• ❌@alloy-js/markdown
• ❌@alloy-js/msbuild
• ❌@alloy-js/python
• ❌@alloy-js/trace-cli
• ❌@alloy-js/typescript

Show changes