ssh-terminfo shell integration doesn't cache installation if connecting to IPv6 address

[injust]

Issue Description

When SSHing to the same server via its domain or IPv4 address, Ghostty will remember that the terminfo has been installed by adding an entry to ~/.local/state/ghostty/ssh_cache.

However, when connecting via its IPv6 address, the file doesn't appear to be created/updated. This results in Ghostty attempting to install the terminfo file on every single connection.

Expected Behavior

Ghostty should use the ssh_cache file to prevent repeated terminfo installation attempts.

Actual Behavior

Ghostty tries to install its terminfo every time I SSH to a server using its IPv6 address.

Reproduction Steps

1. SSH to a server via its IPv6 address (note the "Setting up xterm-ghostty terminfo on" output)
2. SSH again
3. Check ~/.local/state/ghostty/ssh_cache (it will not contain the IPv6 address)

Ghostty Logs

No response

Ghostty Version

Ghostty 1.2.2

Version
  - version: 1.2.2
  - channel: stable
Build Config
  - Zig version   : 0.14.1
  - build mode    : builtin.OptimizeMode.ReleaseFast
  - app runtime   : apprt.Runtime.none
  - font engine   : font.main.Backend.coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

macOS Sequoia 15.7.1

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

shell-integration-features = ssh-terminfo

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[mitchellh]

#9251