feat(marketplace): add batch plugin selection

[FinleyGe]

Summary

• add selectable marketplace cards with a shared bottom batch operation bar
• support batch install in the embedded FastGPT marketplace while filtering already installed plugins
• support batch .pkg downloads in the standalone marketplace and add batch download API coverage

Verification

• git diff --check
• node -e "parse zh-CN/zh-Hant/en app i18n JSON"

Notes

• Local vitest/eslint were not run because this worktree has no node_modules. A frozen install was attempted, but registry downloads stalled before dependencies were linked.

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	18.07%	1598 / 8839
🔵	Statements	18.09%	1680 / 9285
🔵	Functions	15.99%	337 / 2107
🔵	Branches	15.08%	762 / 5050

File Coverage

No changed files found.

Generated in workflow #1376 for commit 9968398 by the Vitest Coverage Report Action

[github-actions]

✅ Admin Preview Image Ready!

ghcr.io/labring/fastgpt-pr:admin_996839800b2de65e51ec09a5239e1b6928df18c4

🕒 Time: 2026-07-10 18:05:43 (UTC+8)

[github-actions]

✅ Build Successful - Preview fastgpt Image for this PR:

ghcr.io/labring/fastgpt-pr:fastgpt_996839800b2de65e51ec09a5239e1b6928df18c4

🕒 Time: 2026-07-10 18:09:03 (UTC+8)