fix: stop test teardowns from silently killing the bun test run

[sneakygriff]

Problem

Several browse/ and design/ test files armed setTimeout(() => process.exit(0), 500) inside afterAll — a workaround for a browser close() that can hang. That assumes each test file runs in its own process. It doesn't: bun test runs every file in one shared process. The 500ms timer therefore fired partway through a later test file and terminated the entire run with exit code 0 and no summary.

Because the exit code was 0, the suite could not gate: only a fraction of the files ran, and every downstream failure was silently masked.

Fix

• Remove the delayed process.exit from teardown; instead time-box resource cleanup. Browser teardowns race close() against a short timeout and abandon it if it hangs (the child is reaped at real process exit). The design daemon /shutdown test stubs process.exit around the shutdown timers so they fire harmlessly.
• Add test/no-suicide-exit.test.ts, a static guard that scans every *.test.ts and fails if any file schedules a delayed process.exit, so the pattern cannot silently return.
• Make test/user-slug-fallback.test.ts deterministic via HOME isolation.

Verification

• bun test test/no-suicide-exit.test.ts test/user-slug-fallback.test.ts — 15 pass, 0 fail (guard green + slug 14/14).
• bun test browse/test/commands.test.ts — 243 pass, 0 fail, now runs to a full summary.
• bun test design/test/daemon.test.ts — 34 pass, 0 fail, no early exit.

Honest note

With the suite now able to run to completion, it surfaces pre-existing failures that the early exit had been hiding — for example design/test/feedback-roundtrip.test.ts fails identically on unmodified origin/main (a session.clearLoadedHtml stub gap), independent of this change. Those failures are not introduced by this PR; this change only makes them visible so they can be gated on and fixed in follow-ups.

🤖 Generated with Claude Code

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