refactor(web-ui): unify remote connection dialog layouts

[bobleer]

Summary

The Devices & Connections views used inconsistent headers, card layouts, and action placement. Give the overview, account, phone/browser, and chat-app pages shared layout and typography, with responsive rows and consistent action bars.

• Group account identity and linked devices into titled sections, keep device actions aligned, and remove duplicate retry actions.
• Consolidate invitation status, label the chat-app execution-detail switch, explain the single active chat-app restriction, and use keyboard-accessible setup links.
• Update English, Simplified Chinese, and Traditional Chinese copy and add presentation/status regression coverage.

Type and Areas

Type: UI/UX, refactor, test.

Areas: Web UI — Remote Connect dialog, account/device panel, locale resources.

Motivation / Impact

Users get consistent navigation and controls across connection methods, clearer setup instructions and status feedback, and usable layouts on narrow screens. Existing account, device-switching, connection, and pairing owners remain in place.

Verification

• pnpm run check:web — passed, including TypeScript, Appearance contracts, typography, all 24 theme color surfaces, and theme visual governance.
• pnpm --dir src/web-ui run test:run src/app/components/RemoteConnectDialog src/infrastructure/design-system/IconUsageIntegration.test.tsx src/app/startup/startupPreload.test.ts — 19 files, 187 tests passed.
• pnpm run i18n:audit — passed, 0 warnings.
• pnpm --dir src/web-ui run icons:check — passed.
• pnpm run motion:audit — inspected; no new motion findings in the changed files.
• git diff --cached --check — passed before commit.
• node scripts/check-git-object-sizes.mjs --base upstream/main --head HEAD — passed.
• Browser checks with production components and mocked service boundaries: overview, account/device rows, alias editing, LAN settings and invitation QR at 375px, and English Feishu setup in dark mode. Compared the Feishu view with the previous revision.

Reviewer Notes

AI-assisted review and submission. Testing level: lightly tested end to end; focused frontend checks passed.

Remote control and Peer Device Mode have frontend fixture coverage only. Real remote workspace, remote control, Peer Device Mode, and Detached Dispatch environments were not exercised. No backend command, wire protocol, or persisted data shape changes are included.

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.