Phone terminal: tap opens links, keyboard no longer toggles on tap

[pallaoro]

Summary

• SwiftTerm tied keyboard visibility to first-responder status, so on the phone every tap on the terminal output flipped the keyboard, link taps were gated behind a hover check touch can never satisfy, and the bridge's open-link callback was empty.
• The terminal now stays first responder and shows or hides the keyboard by swapping its input view. A tap opens a link, else clears a selection, else asks for the keyboard when near the cursor row. A tap never hides the keyboard; the Hide button does.
• Tapped http(s) URLs are forwarded to JS and opened with Linking. The keyboard-visible hook and the post-keyboard repaint nudge now key off keyboard frame changes, since an empty input view is reported as a frame change rather than a hide.

Verification

• Built and run in the iPhone 15 Pro simulator against the Hetzner box over Tailscale.
• Tapping a row of the wrapped Claude Code /login URL opened Safari with the full URL and the login completed on the box.
• Keyboard stayed down through the flow; no show/hide ping-pong.
• Not yet exercised by touch: long-press selection + Copy with the keyboard down, and the Hide button round trip.