fix(status): scroll long extension labels while preserving explicit line breaks

[YsDirector]

Summary / 概述

In narrow mobile views, long extension status labels wrapped onto several lines and crowded the bottom of the chat area. Long labels now stay on one line and scroll horizontally, while explicit line breaks from extensions remain intact. Multiline reports such as /wechat-status retain the existing height cap and vertical scrolling.

手机模式下，底部状态栏的超长标签会自动换行成多行、挤占屏幕空间。本 PR 让长标签保持单行并横向滚动，同时保留扩展主动输出的换行。/wechat-status 等多行报告继续使用原有高度上限和纵向滚动。

Before / 修复前截图

The long LLM Wiki status label wraps to roughly five lines instead of one.
超长状态标签自动换行成约 5 行，而不是单行。

Change / 改动

• app/globals.css: use white-space: pre to preserve explicit newlines without wrapping long lines. The status container handles both scroll axes, remains top-aligned, and retains the existing 144px / 18dvh height cap.
• components/ExtensionStatusBar.test.mjs: update the regression assertions for preserved line breaks, disabled automatic wrapping, and bounded scrolling.

长标签可横向滚动，多行报告保留分行结构；纵向内容超过高度上限后，可在状态栏内滚动查看。

Verification / 验证

• node_modules/.bin/tsc --noEmit --incremental false passed.
• npm run lint passed.
• 23 related component tests passed: ExtensionStatusBar, ExtensionWidgets, and AnsiText.
• 30 Chromium component layout checks passed at 320px, 390px, and 1280px widths, with and without widgets. Cases cover short labels, long ANSI-colored labels, explicit multiline reports, tall reports, and reports overflowing both axes. Checks verify line counts, height limits, first/last character visibility after scrolling, and no page-level horizontal overflow.