Wrap the update-log and job-output pre blocks the app shell was clipping

[atomantic]

Summary

• Layout.jsx's root is overflow-x-hidden, so a <pre> wider than the viewport is clipped, not scrollable — the tail is unreachable with no horizontal scrollbar to find. Two <pre> openers still had no wrap or overflow class at all: the self-update log (UpdateTab.jsx) and the read-only legacy script command (JobCard.jsx). Both now match the ProcessLogLines idiom (whitespace-pre-wrap break-all), with the update log additionally capped at max-h-48 overflow-y-auto so a long log doesn't push the rest of the tab off-screen.
• Local review caught the same defect one layer down: JobCard's two other output blocks had whitespace-pre-wrap but no break class, which only wraps at whitespace. A shell job's last output is full of unbroken paths and URLs that still ran past the clip edge, so it gets break-all. The prompt template beside it gets break-words instead — it is human-authored prose, where breaking mid-word is worse than the rare long token.
• Layout.jsx's overflow-x-hidden is untouched, per the issue: it is deliberate, and the fix belongs in the leaf.
• Out of scope, worth a follow-up: 33 other <pre> blocks tree-wide carry whitespace-pre-wrap with no break class. Most render prose and are fine; a mechanical sweep of the machine-output ones is separate work.

Test plan

• client/src/components/cos/JobCard.test.jsx (new): renders a legacy script job in edit mode and asserts the command <pre> carries whitespace-pre-wrap break-all; renders a shell job with a long unbroken lastOutput and asserts break-all.
• client/src/components/apps/tabs/UpdateTab.test.jsx: new case supplying a long space-free lastUpdateResult.log and asserting whitespace-pre-wrap, break-all, and overflow-y-auto.
• Each new assertion was verified as a real guard by reverting the class it pins and confirming the test goes red.
• cd client && npx vitest run src/components/cos src/components/apps/tabs — 634 passed (52 files).
• cd client && npx biome lint --error-on-warnings src/components/cos src/components/apps/tabs — clean.
• Acceptance grep from the issue returns no single-line results.

Closes #5675