feat(mcp): add Parallel Search to marketplace

[georgeatparallel]

Summary / 概要

• Adds Parallel Search as an optional recommended remote MCP server in Kun's existing plugin marketplace.

Why / 背景

• Gives users a native way to add live web search and URL fetching without manually editing MCP JSON or supplying an account or API key.

Changes / 变更

• Registers https://search.parallel.ai/mcp through the existing secure remote-MCP configuration path with network-only supply-chain permissions.
• Adds focused marketplace coverage and localized card copy for all seven active application locales.
• Preserves Brave Search and every existing marketplace item, default, and runtime behavior.

Media / 截图或录屏

• Not attached. This is a data-only addition to the existing marketplace card layout and interaction path.

Tests / 测试

• PluginMarketplaceView.test.ts (32 tests passed)
• Parallel Search locale-key presence check (7/7 locales)

Validation / 验证

• I agree that this contribution is submitted under the Contributor License Agreement. / 我同意本贡献遵循 Contributor License Agreement 提交。
• npm run test
• npm run typecheck
• npm run build
• npm run dev (if runtime or UI behavior changed / 如果运行时或界面行为有变化)
• UI change: video or GIF attached / 界面变更：已附上视频或 GIF
• Logic change: unit tests added or updated / 逻辑变更：已新增或更新单元测试

Notes / 备注

• npm run typecheck currently reports errors in existing provider settings and credential-readiness tests outside this change.
• The combined locale test reaches existing settings.json parity failures in five locales after the marketplace tests pass. The two new common.json keys are present in all seven locales.
• The full test command completed extension tests but did not exit after the Kun runtime suite became idle; the focused marketplace suite passes.

Disclosure: I work at Parallel.ai, which operates this MCP endpoint.