#3594 [GUI] serve/web: keep wide content (long URLs, code lines, wide tables) inside the viewport on narrow screens

Descripción

Supersedes #2667 (closed in the 0.2.0-beta tracker reset; branch rebased onto current `main`).

**Area:** [GUI]

## Problem and result

On a narrow screen (phone), an assistant reply containing one long unbroken string (URL, code line) or a wide table stretches the chat column past the viewport: the right side is clipped and unreachable, and the page heading and composer shift with it. After the change the assistant text breaks long strings, wide tables scroll inside their own bubble, and the column stays at viewport width.

## Related discussion

none

## Approach

`serve/web/app.css` only, two rules:

- `.st-msg--assistant .st-bubble { width: 100%; overflow-wrap: anywhere; }` — the assistant bubble now breaks long unbroken strings, matching the user bubble, which already carried `overflow-wrap: anywhere`.
- `.st-bubble table { … display: block; max-width: 100%; overflow-x: auto; }` — wide tables scroll horizontally inside their bubble instead of widening the column.

The `.view { min-width: 0 }` guard from the original revision is already present on `main` (line 7 of this file), so this revision no longer touches it. Desktop layout is unchanged.

## Validation

**Passed:** measured at a 390×844 viewport against 0.1.44.1 with three messages (long URL / long code line / wide table): before — chat column 752 px, bubbles 718 px, right edge 346 px off-screen; after — column 390 px, bubbles 356 px, everything on screen (the URL wraps, the code block and the table scroll inside themselves). Desktop at 1280 px: no overflow before or after, normal prose unaffected.

**Failed:** none observed.

**Not run:** not re-measured on 0.2.0-beta — the rebase re-applied the two rules onto current `main`, where the CSS they touch is unchanged; the measurements above are from the original 0.1.44.1 revision. No browser engine other than Chromium was tested.

## Limits

Firefox and Safari not tested. `overflow-wrap: anywhere` permits mid-word breaks in assistant prose — accepted trade-off, and already the behaviour of user bubbles.