## Summary

- Contain long code, tables, and tab strips in native horizontal scrollers with a persistent compact-width affordance. - Wrap authored headings, tab labels, and callout titles; keep the selected/focused tab revealed across keyboard selection and strip resizing. - Keep compact table drag grips in the gutter and expose the existing 44px action toolbar without overlapping table content. - Add one hostile-content fixture plus compact and desktop behavior coverage. Mermaid rendering remains unchanged and out of scope.

## 390×844 evidence

| Surface | Before on `main` | After | | --- | --- | --- | | Page | `390 / 390` client/scroll width | `390 / 390` | | Code | `350 / 1378`; no perceptible scrollbar | `350 / 1378`; 8px scrollbar, 1028px reachable range | | Table | `350 / 1979`; no perceptible scrollbar | `350 / 1979`; 8px scrollbar, compact grips/actions reachable | | Tabs | `350 / 1817`; last tab at x=1470…1837 | `350 / 1800`; selected tab inside strip at scrollLeft=1450 |

## Verification

- `bun test` — 853 passed, 2 database-only skips - `bun run types` - `bun run ci` - `bun run build` - Responsive/table browser pass — 37/37 - Complete browser suite — 180/180