ci: nightly browser suite

[opticon454]

What

A scheduled (03:17 UTC) and manually runnable GitHub Actions workflow, Browser suite, that runs npm run test:browser on a clean ubuntu runner (Node 22, tmux, playwright install --with-deps chromium). It is informational only: it is not a merge gate and never blocks a push or PR. The per-push gate (npm test) is unchanged; ci.yml only gains a two-line comment pointing at the new job.

Why

config/test-suites.ts keeps the Playwright suite out of the per-push gate, which means a browser-only regression (the Shift+Enter keypress bug was one) can merge green. Running it nightly catches those within a day. It needs no secrets: the tests start their own server and drive a local chromium.

Left out on purpose: test:mobile (per-machine PNG baselines), test:perf (wall-clock), and test/codex-predictive-echo.test.ts (needs a real, authenticated codex binary).

Evidence

I ran it on a fork to see whether it can be green on a clean runner. First run: 119 passed, 5 failed. The failures were stale or environment-dependent tests rather than product bugs, so this PR also fixes them:

• test/opencode-resize.test.ts
  • session-id extraction read data.id, but POST /api/sessions answers { success, data: { session } }.
  • resizes now travel as WebSocket {t:'z'} frames while the socket is up, so the test records those as well as POST /resize.
  • the needsRefresh test only resizes after replaying a non-empty buffer, so it now seeds real PTY output first.
  • the "Kill Tmux & OpenCode" test is skipped when opencode is not installed.
• test/split-pane-terminal.browser.test.ts: plain <text>\r input goes through tmux send-keys, which test mode does not have, so the marker never landed. It is now sent with useMux:false and retried past Codeman's own post-create clear.
• test/perf-browser.test.ts: same session-id envelope fix.

Latest fork run (before #534 landed, on 1.34.0): 122 passed, 1 skipped, 1 failed, the one failure being test/inline-rename.test.ts (rail rename editor clamped), a real product bug that #534 / #526 have since fixed on master. This branch is rebased onto 1.35.0 and inline-rename, opencode-resize and split-pane-terminal pass locally (36 passed, 1 skipped for the OpenCode-not-installed case), so the first nightly run should be green. I have not re-run the whole suite on a runner since the rebase: Actions → Browser suite → Run workflow after merge is the quickest confirmation.

Notes

• No new dependencies and no secrets; permissions: contents: read.
• Artifacts are uploaded on failure only.
• To try it before merging: Actions → Browser suite → Run workflow.

🤖 Generated with Claude Code

https://claude.ai/code/session_01JrzFKEdBLwVfu6ev2ZscJS