ci: run the test suite on every push and PR

[snehithareddy28]

What & why

The repo ships 107 node:test files — 834 tests documenting real fixed bugs (hive routing, the circuit breaker, Windows cmd-shims, Arabic/RTL, the updater) — but CI never executes them. The effective merge gate today is tsc --noEmit plus the release-link check, so a change can silently re-break any tested behaviour and still merge.

This adds one npm run test:focused step to the existing Typecheck job, which already does the npm ci the tests need. On a fresh checkout of main the suite passes 834/834 in about ten seconds locally and about twenty-five on the runner — a real regression gate for well under a minute of CI, with no second npm ci, no new runner and no matrix change.

Rebased onto current main (6248293a); ci.yml has not moved since this was opened, so it still applies cleanly.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Docs
• Build / CI

Evidence

Before

After

The after image is this pull request's own Typecheck job, so the evidence is the change running against today's main rather than a reconstruction.

---

Notes for review:

• The step sits between Typecheck and the release-link check inside the existing job: no second npm ci, no new runner, no matrix change.
• Verified just now against 6248293a: pristine main passes 834/834, and main with my three open fixes (fix(hooks): make an unbound hook socket loud, self-healing and visible #495, fix(worktree): never auto-discard a named agent's unintegrated work on PTY exit #496, feat(agents): reopen a closed agent instead of only deleting it #503) merged together passes 852/852 — so turning this on does not turn main red, today or once those land.
• Since this PR was opened, four PRs with tests have merged or are open against a CI that runs none of them (fix(breaker): hash the toolKey so long-prefix Bash commands don't collide #424, fix(breaker): a live human conversation counts as progress #425, fix(breaker): measure the per-agent token cap in work tokens, not cached context #426 merged; fix(hooks): make an unbound hook socket loud, self-healing and visible #495, fix(worktree): never auto-discard a named agent's unintegrated work on PTY exit #496, feat(agents): reopen a closed agent instead of only deleting it #503 open with 18 tests between them). This is the step that makes those tests mean something.
• The comment on the step carries the current file/test counts rather than the ones from when this was first written.
  Discord: asr2805

[snehithareddy28]

A current data point for this one, since main has moved a lot since it was opened.

Three PRs with tests have merged since (#424, #425, #426) and #495 is up with six more — none of them run in CI today, because the Typecheck job still has no test step. This branch is unchanged and still applies cleanly to current main (ci.yml has not moved).

The evidence runs for #495 execute exactly this step against today's main: 840/840 in ~30 s on macos-latest, and the same step catching a regression when the fix is left out.

Happy to rebase or squash anything if you'd like it in a different shape.