chore: upgrade deps, lint, node v26 support.

[knightedcodemonkey]

No description provided.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.40%. Comparing base (2471371) to head (11c593b).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #55   +/-   ##
=======================================
  Coverage   93.39%   93.40%           
=======================================
  Files          26       26           
  Lines        5196     5197    +1     
  Branches     1149     1149           
=======================================
+ Hits         4853     4854    +1     
  Misses        305      305           
  Partials       38       38           

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[Copilot]

Pull request overview

This PR updates project tooling and dependencies to support newer Node/TypeScript versions (including Node 26), introduces ESLint alongside oxlint, and applies resulting lint/import-order cleanups across source, tests, docs, fixtures, and CI.

Changes:

• Add ESLint flat config and wire it into npm scripts / lint-staged, while simplifying oxlint.json.
• Update engines/docs/CI to include Node 26 and upgrade TypeScript + related dependencies.
• Refactor various exports/types and reorder imports to satisfy updated linting rules.

Reviewed changes

Copilot reviewed 41 out of 43 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tsconfig.test.json	Remove explicit types override so Node types flow from base tsconfig.
tsconfig.json	Add Node types globally for the project.
test/utils.ts	Import ordering adjustments for lint rules.
test/specifier.ts	Import ordering adjustments for lint rules.
test/module.ts	Import ordering + replace block eslint disable with targeted eslint-disable-next-line.
test/fixtures/specifier/specifier.mjs	Import ordering adjustments for fixture linting.
test/fixtures/projects/ts-webapp/src/ui/app.tsx	Import ordering adjustments for fixture linting.
test/fixtures/projects/ts-webapp/src/main.tsx	Import ordering adjustments for fixture linting.
test/fixtures/projects/cjs-app/index.cjs	Require ordering + spacing adjustments for fixture linting.
test/fixtures/meta.mjs	Import ordering adjustments for fixture linting.
test/fixtures/complexFile.mjs	Import ordering + whitespace adjustments for fixture linting.
test/fixtures/complexFile.cjs	Require ordering + whitespace adjustments for fixture linting.
test/cli.ts	Import ordering + update TS config JSON used in tests to set rootDir.
src/walk.ts	Import ordering adjustments.
src/utils/lang.ts	Whitespace adjustment (import grouping).
src/utils/identifiers.ts	Reorder imports and reduce exported surface to only what’s used.
src/utils/exports.ts	Remove unused requireMainRgx export and constant.
src/specifier.ts	Reorder imports and reduce exported types.
src/pipeline/lowerEsmToCjs.ts	Reorder imports and stop exporting internal helper exportAssignment.
src/pipeline/lowerCjsRequireToImports.ts	Reorder imports.
src/pipeline/idiomaticPlan.ts	Stop exporting internal plan result types.
src/pipeline/formatVisitor.ts	Import grouping/order adjustments.
src/pipeline/buildEsmPrelude.ts	Import ordering adjustments.
src/module.ts	Import reordering and eslint disable comment adjustments (but currently introduces duplicate imports).
src/helpers/identifier.ts	Import ordering adjustments.
src/helpers/async.ts	Import ordering adjustments.
src/helpers/ast.ts	Reduce exported type surface (keep internal helper types unexported).
src/formatters/identifier.ts	Import ordering adjustments.
src/formatters/expressionStatement.ts	Remove unused formatter implementation file.
src/formatters/assignmentExpression.ts	Import ordering adjustments.
src/format.ts	Import ordering/grouping, minor type export change, and eslint-disable comment tweaks.
src/cli.ts	Import ordering/grouping and eslint-disable comment tweaks.
README.md	Update Node version requirements and add TS6 rootDir note.
package.json	Node engine update, dependency upgrades, add ESLint scripts, add overrides, update lint-staged.
oxlint.json	Simplify rules, adjust overrides (fixtures).
eslint.config.js	Add ESLint flat config (import/order + import/no-unused-modules).
docs/esm-to-cjs.md	Update runtime requirements text to match engines.
docs/cli.md	Update Node requirements text to match engines.
docs/cjs-to-esm.md	Update runtime requirements text to match engines.
.github/workflows/publish.yml	Update action versions and publish Node version to 26.
.github/workflows/ci.yml	Expand CI Node matrix to include 26 and update action versions.
.eslintrc.json	Add legacy ignorePatterns file (note: ESLint v9 uses flat config by default).

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