fix(desktop): detect Kimi Code in its default install path

[benthecarman]

Summary

By default on linux kimi is installed at ~/.kimi-code/bin/kimi and this was not detected automatically. This now fixes it by adding this path to the detection

Related issue

N/A

Testing

Before it did not appear / did not detect. Now it does :)

[felirami]

Confirming this also reproduces on macOS, so the fix is cross-platform, not Linux-specific.

Diagnosis from an affected machine (Buzz 0.5.3, kimi-code 0.31.1):

• The desktop app launched via Finder inherits launchd's default PATH=/usr/bin:/bin:/usr/sbin:/sbin.
• kimi-code's installer appends ~/.kimi-code/bin to PATH in ~/.zshrc (interactive shells only), which a login shell (zsh -l -c 'command -v kimi') never sources — so the find_via_login_shell fallback in discovery.rs also misses it. Verified with env -i HOME=$HOME PATH=/usr/bin:/bin:/usr/sbin:/sbin /bin/zsh -l -c 'command -v kimi' → not found.
• ~/.kimi-code/bin is absent from common_binary_paths(), so resolution fails at every stage. This mirrors the existing nvm special-case a few lines below ("~/.zshrc (interactive) which is not loaded by a login shell").

Adding ~/.kimi-code/bin to common_binary_paths() fixes detection regardless of the user's shell configuration. Would love to see this merged — until then the workaround for affected users is adding the export to ~/.zprofile.