[raiseCatError]

What changed

tests/browserConsoleChrome.test.ts (test "a reload starts a new document; NMSh's find world, web pages and the Mermaid renderer never report"): when the assertion fails, it now prints the renderer's result. The assertion itself is unchanged:

assert.ok(result.ok || result.code === 'syntax', result.ok ? undefined : JSON.stringify(result));

On success the result carries the drawn PNG, so the message is only built when the render failed. The timeout (10 s) and the rest of the test are unchanged.

Why

This assertion fails intermittently on hosted macOS CI, and the failure output never shows which code the renderer returned (timeout, crashed or failed, from src/browser/engine/diagram.ts):

• run 40630147755 (Hold ambiguous program input for explicit recovery #514), macOS 1/3: failed at line 106 after 13.9 s
• run 43064876487 job 130677155629 (Rex support (experimental): host semantics and OSC 7501 program status #543 head cece7ed9), macOS 1/3: failed at line 106 after 17.3 s

Neither PR touches browser or diagram code. Both durations are consistent with the 10 s render timeout, but the logs don't prove it. With this change, the next failure records the code and reason.

Verification

• tsc --noEmit and git diff --check are clean.
• One focused local run passed (4.6 s), but it did not exercise the renderer. Mermaid isn't installed on the local Mac and NMSH_TEST_MERMAID was unset, so locateMermaid returned not-ok and the test silently skipped the render step. CI installs Mermaid 12.2.0 for this test, so this PR's macOS CI shards are the run that matters.

No human terminal testing is needed; this changes test output only.