The terminal's sign-ins screen revokes one of your API tokens with `d` after a confirm, never showing the token #7441

Intent: the owner who sees an unknown token in use ends it in the same place they saw it.

Today src/tui/screens/signins.ts lists your tokens beside your browsers, but says a token is revoked from Settings → Personal access tokens. Only browser sessions can be ended there.

Done:

• [ ] With a token row selected, d asks Revoke <name> (<scope>)? It stops working at once. and on yes calls deleteToken(db, you, id) from src/core/tokens.ts. That only ever removes your own token.
• [ ] The token used by this very connection (if any) is marked and cannot be revoked from here, with one line saying why.
• [ ] The screen's header comment no longer sends people to Settings for this.
• [ ] A test (e.g. test/tui-signins-token.test.ts) makes two tokens, revokes one after a confirm (it no longer verifies, the other still does), checks a cancelled confirm changes nothing, and checks no frame holds a token value.

Files: src/tui/screens/signins.ts, a new test.