ci: merge gate — Biome, Vitest, expanded E2E/visual, Husky hooks

[chtnnh]

Summary

• Replace ESLint with Biome (root biome.json, format + lint across the monorepo).
• Redesign GitHub Actions CI into a merge gate: quality → build → unit → db → e2e → visual, with Playwright artifact uploads on failure.
• Add Vitest workspace and unit tests across all packages; migrate logic from several slow Playwright specs.
• Expand Playwright E2E (desktop + mobile) and visual regression baselines; add @smoke suite and shared room helpers.
• Add Husky hooks: incremental ci:pre-commit, fast ci:pre-push (quality/build/unit/db only — E2E/visual run in CI), plus pnpm ci:local for full parity.
• Document local dev, ci:* scripts, testing layers, hooks, and optional know-code workflow in README / CONTRIBUTING / AGENTS.

Test plan

• CI green on this PR (quality, build, unit, db, e2e, visual jobs)
• pnpm ci:local passes locally
• pnpm ci:pre-commit on a small change (~30–90s)
• pnpm ci:pre-push completes without Playwright (~1–5 min)
• Spot-check: create room, chat, queue reorder on mobile + desktop

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
together-web	Ready	Preview	Aug 7, 2026 6:03pm

[cursor]

PR Summary

Medium Risk
Mostly CI, lint, and test infrastructure; low runtime risk, but a misconfigured hook or CI job could block merges or miss regressions until green CI is verified.

Overview
Introduces a documented merge gate (pnpm ci:local) aligned with GitHub Actions: split jobs for quality (Biome + typecheck), build, unit (Vitest), db guard, e2e, and visual, with shared workflow env and Playwright report/test-result artifacts on failure.

Replaces ESLint with Biome at the repo root and in @together/web; removes eslint.config.mjs. Adds Husky pre-commit / pre-push wired to ci:pre-commit and ci:pre-push, plus optional gitignored know-code hook examples and CONTRIBUTING.md for the contract.

Testing changes: Vitest workspace and test:unit / ci:unit; many former Playwright-only assertions move to unit tests (playback sync, rate-limit helpers, crossfade, etc.). Playwright gets mobile-first project ordering, broader mobile E2E coverage, @smoke specs, richer e2e/helpers/room.ts (tabs, settings, promote bar), failure screenshots/traces, and new visual baselines (offline, private join, settings).

Small product/testability tweaks: chat uses shared mention helpers and data-testids with LTR chat on RTL pages; admin layout force-dynamic; infra e2e asserts the new CI scripts and Biome.

^{Reviewed by Cursor Bugbot for commit cb6398f. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 3 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit d7a37c3. Configure here.}