fix(content): update console screenshot titles and captions

[mrgoonie]

Updates the titles and captions in src/content/ccp-screens.ts to describe the current console, following the console docs rewrite in #36.

• Captions now match current behaviour: hooks allow, block or add context (not webhooks); chat can approve or deny requests; skill templates are starting points for new agents; MCP servers need a grant before agents can use them; built-in tools show risk and must be enabled; API keys & docs has Docs, Audit and MCP client setup; settings save together; members include pending invites.
• Titles use the app's nav labels in en and vi (for example API keys & docs / API key & tài liệu, Kỹ năng, Máy chủ MCP, Công cụ có sẵn, Lịch, Workflow, Tin nhắn đang chờ, Sao lưu).
• Screenshot images (cdn v1) are unchanged.

Validation: pnpm test 416 passed, pnpm check 0 errors, pnpm build complete; captions render on the docs pages in en and vi.