fix(ui): shrink-wrap floating menus and align terminal font and global search spacing

[kev1n77]

Summary

This PR fixes four reported Web UI defects: floating menus reserved a fixed width and read far too wide for short labels, the terminal rendered larger than the code surfaces beside it and fell back to SimSun for Simplified Chinese, the select-all row in the terminal and editor menus used a dashed placeholder glyph, and the global search count and back pills looked lopsided around their chevrons. All changes are presentational; no product behavior, protocol, or persisted shape changes.

Type and Areas

Type: bug fix (UI/UX)

Areas: web UI (desktop Web UI; design system packages ui and design-tokens)

Motivation / Impact

• Floating menus (right-click context menus, and the sidebar settings, theme, session, workspace, session filter, and assistant menus) reserved the default menu width, so short labels, their shortcut column, and submenu chevrons sat far apart behind a wide empty gutter. Menus can now shrink-wrap their widest row; the default stays fixed so anchored pickers are unaffected.
• ActionItem shortcut hints had no typography rule of their own and inherited the surrounding body size, so Ctrl+Shift+C rendered larger than the 13px label next to it. They now use the meta role, matching SearchField.
• The terminal select-all row used BoxSelect, which is an alias of SquareDashed, so it read as a dashed placeholder box. It now draws a solid SquareCheckBig glyph in both the terminal and editor menus.
• The interactive terminal took font.size.base (14px) while the in-chat terminal preview and every other code surface take the xs step (12px), so a shell panel rendered noticeably larger than the code beside it. font.family.mono also named no CJK family, so Simplified Chinese fell through to the platform generic monospace face (SimSun on Windows). The terminal now shares the xs step, re-reads it on the global font preference change, and renders CJK with the same UI families as the rest of the interface.
• The global search group count pill and the drilldown back pill were lopsided, and padding was not the cause: a lucide chevron inks only x 9..15 of its 24 viewBox, so a square Icon box stays about 34% empty on each side (roughly 5px at the 14-15px boxes these surfaces render). Both pills now cancel that slack on the edge that meets their inline padding, and the back button's asymmetric 3px 6px 3px 4px padding is symmetric.

Verification

• pnpm --dir design-system run test (token-engine, design-tokens 37, theme 12, ui 283, package-contract, design-lab 61, plus type-check)
• pnpm --dir src/web-ui run test:run src/shared/context-menu-system (28 passed)
• pnpm --dir src/web-ui run test:run src/app/components/NavPanel (202 passed)
• pnpm --dir src/web-ui run test:run src/tools/terminal (44 passed)
• pnpm run type-check:web
• pnpm --dir src/web-ui exec eslint on the changed files
• pnpm run data-migrator:theme:check
• pnpm run check:web:appearance (typography audit, appearance contracts, theme color audit, theme visual contract); it reports the same pre-existing warnings as the base branch
• Manual checks: right-click menus in the terminal and editor and the sidebar action menus (row-sized width, shortcut hint size, solid select-all glyph), the terminal at the default and a larger global font size, Simplified Chinese output in the terminal, and the global search count pill hover plus a group drilldown

Two spots are deliberately not pinned by tests yet: the terminal font size, and the two global search declarations. The global search change was validated against compiled stylesheet output, where the visible insets were 4.5px leading against 8.8px trailing on the count pill and 9.1px against 6.5px on the back pill, and now match.

Reviewer Notes

• Menu gains an opt-in inlineSize="content": the widest row sets the width, floored by the new overlay.menu.minInlineSize token (160px) and still capped by overlay.menu.inlineSize (220px). The default remains a fixed width so anchored pickers and comboboxes keep matching their control.
• The CJK families are appended after the Latin monospace families and before the generic keyword, which is the only correct position: a proportional CJK face placed earlier also supplies Latin glyphs and would take code rendering off the monospace grid. The generated data-migrator stylesheet and the MiniApp first-paint projection are regenerated from the token.
• The global search chevron slack is a single local $chevron-box-slack constant placed next to the documented glyph geometry, because it tracks the rendered chevron size rather than the spacing scale.
• Known follow-up, intentionally out of scope: the open/new project and recent workspace menu in MainNav.tsx keeps its local fit-content width with a min(440px, ...) cap because long paths and hostnames need it, while the shared content cap is 220px. Migrating it needs the cap raised by a token first.
• Each commit is independent and reverts on its own; the token commit and its regenerated artifacts must stay together.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.