fix(desktop): 本地化设置页 Agent 文案

[Xavier-Trump]

Summary

• Localize Settings runtime descriptions in the display layer, including the Orchestrator Agent metadata returned by Edge.
• Localize Agent Market preview agents, template cards, capability tags, tool labels, and source labels while preserving product terms such as Agent, MCP, Hub, Runtime, Codex, OpenCode, and Claude Code.
• Keep user/Hub-provided Agent content unchanged; only built-in preview/runtime metadata is translated.

Validation

• cd app/desktop && corepack.cmd pnpm typecheck
• zh/en JSON parse
• Settings locale key sync scan: missing zh/en keys = 0, missing literal settings keys = []
• Playwright zh Settings probe: no English description hits, Orchestrator/Market/template Chinese assertions true, console errors empty
• git diff --check for touched Settings/i18n files