MCP claim_link answers the one line of what the recipient will see first, beside the link #11494

Intent: an agent that makes a forge for a client can say, in the same breath as the link, what the client will see.

Done:

• [ ] claim_link includes firstScreen, the sentence from firstScreenLine(apps) in src/core/next-steps.ts, for the forge's chosen apps
• [ ] The words are not copied: the tool and the clients page read the one function
• [ ] A test asserts the field for two apps and for none, and fails without the change
• [ ] bun test test/mcp-size.test.ts passes

Files: src/http/mcp/tools/claim_link.ts, test/mcp-claim-first-screen.test.ts

Risks: none beyond tools/list bytes. Suggested: scout.