Add Oxlint as complementary JS/TS linter with tsgolint integration

[gregkonush]

Summary

Adopt Oxlint across the monorepo as a complementary JS/TS linter alongside existing tooling (Biome, ktlint, gofmt, buf, etc.), and integrate type-aware checks via tsgolint where supported. This should add new lint entrypoints without replacing current ones.

Context

• JS/TS linting today is Biome-centric (root biome.json, workspace scripts call bunx biome check or biome lint).
• CI workflows invoke Biome checks per app/service.
• Type-aware linting is desired, but tsgolint (typescript-go) has limitations (e.g., baseUrl in tsconfig).
• Many generated artifacts are excluded in Biome and should remain excluded in Oxlint.

Desired Outcome

• Oxlint configured at the repo root with shared rules and ignore patterns.
• New scripts for Oxlint (non-type-aware and type-aware variants) added without removing existing lint scripts.
• Optional type-aware linting enabled per workspace based on tsconfig compatibility.
• CI runs Oxlint as an additional check (non-blocking or phased to blocking).
• Clear docs for developers on when/how to run Oxlint and how it coexists with Biome.

Scope

• In scope:
  • Root Oxlint config (e.g., .oxlintrc.json) and ignore rules.
  • New lint scripts in root and workspace package.json files.
  • CI workflow updates to add Oxlint checks.
  • Lint-specific tsconfig(s) (as needed) to enable --type-aware.
  • Docs updates describing dual-tool workflow.
• Out of scope:
  • Removing or replacing Biome, ktlint, gofmt, buf, or other existing linters.
  • Large-scale code reformatting.
  • Changing production infra or ArgoCD manifests.

Constraints & Risks

• tsgolint/type-aware mode uses typescript-go and does not support some TS options (notably baseUrl), which may require lint-only tsconfigs.
• Oxlint config is JSON-only and nested configs do not merge; enforce a single canonical config.
• Avoid lint noise on generated or vendored files.

Rollout / Ops Notes

• Start with a pilot workspace (e.g., apps/froussard or packages/codex) and run Oxlint side-by-side with existing lint.
• Expand to remaining workspaces after tuning rules and ignore patterns.
• Consider non-blocking CI at first, then switch to blocking once stable.

Validation

• bun run lint:oxlint (repo or workspace) passes on pilot workspace.
• bun run lint:oxlint:type passes on pilot workspace where enabled.
• Existing lint commands (Biome, ktlint, gofmt, buf) still pass.
• CI workflows include Oxlint step and stay green.

Codex Prompt

Implement Oxlint as a complementary JS/TS linter in this monorepo (do not replace existing tooling). Add root Oxlint config + ignore patterns mirroring current Biome excludes, install oxlint and oxlint-tsgolint, and add new lint scripts (e.g., lint:oxlint, lint:oxlint:type) alongside existing ones. Introduce lint-specific tsconfig(s) to enable oxlint --type-aware where compatible (avoid unsupported TS options like baseUrl). Update CI to run Oxlint as an additional check with phased enforcement. Update docs describing the dual-tool workflow. Focus on JS/TS workspaces only; do not touch infra or generated directories.

Additional Context

• Repo root biome.json already lists many generated file excludes; port these to Oxlint ignore patterns.

[linear]

PROOMPT-192

[gregkonush]

• Add Oxlint config/ignores and dependencies.
• Add Oxlint scripts and type-aware pilot for services/bumba; document usage.
• Wire Oxlint into CI (non-blocking) for bumba via common workflow.
• Run required checks (Biome + Oxlint + bumba tests).

Status: ready for review.
PR: #2203

Validation:

• bunx biome check package.json services/bumba/package.json README.md .oxlintrc.json .github/workflows/common-monorepo.yml .github/workflows/bumba-ci.yml
• bun run lint:oxlint
• bun run lint:oxlint:type
• bun run --cwd services/bumba tsc
• bun run --cwd services/bumba test