Bug: reportPwd Url is not encoded

[achwo]

When changing the pwd, the url is not correctly encoded in the shell integrations (except fish). This breaks inheriting the working directory for new tabs / windows with paths with special characters.

Example with zsh:

1. cd /Path/With/Special/Char??
2. terminal integration report_pwd sends: kitty-shell-cwd://host.name/Path/With/Special/Char??
   

   ghostty/src/shell-integration/zsh/ghostty-integration

   Line 189 in ddf7173

   _ghostty_report_pwd() { builtin print -nu $_ghostty_fd '\e]7;kitty-shell-cwd://'"$HOST""$PWD"'\a'; }

3. in stream_handler.zig url is parsed and the ?? are lost, because it is not url encoded: kitty-shell-cwd://host.name/Path/With/Special/Char
   

   ghostty/src/termio/stream_handler.zig

   Line 1088 in ddf7173

   const uri = std.Uri.parse(url) catch |e| {

4. path is not accessible -> fallback to / in new tab

I could provide a PR for zsh and probably bash, but I'm not 100% sure that encoding here is the right solution, or if it should be handled differently in stream_handler.zig. Especially since bash and zsh don't provide any url encoding builtins afaik. What do you think?