[Astro-Han]

Summary

When Maka.app or maka-desktop-shell is opened directly from Finder, the Dock, Spotlight or a Linux desktop launcher, it inherits only the desktop session's minimal PATH (for example /usr/bin:/bin:/usr/sbin:/sbin under macOS LaunchServices). The Host spawned by maka desktop inherits that stripped PATH, so external agent CLIs (agy, codex, claude) and MCP servers installed in ~/.local/bin or Homebrew report as not installed.

Before maka-desktop-shell's direct-launch bootstrap spawns maka desktop on Unix, capture PATH from the user's interactive login shell when neither TERM nor COLORTERM is set (and MAKA_SKIP_SHELL_ENV is not 1), then pass that PATH to maka desktop so both the Host and subsequent Host reconnections inherit it:

• Keeping resolution inside maka-desktop-shell's direct-open bootstrap leaves CLI invocations and env_clear() integration test sandboxes untouched.
• Importing only PATH prevents shell startup files from injecting application-control environment variables, and shell stderr is sent to /dev/null so startup secrets are never retained or logged.
• Executing /bin/sh inside the login shell ensures shells where $PATH is a list (fish, nu, csh/tcsh) export a standard colon-delimited PATH before printing it between per-run UUID markers.
• Running the probe in its own setsid() session/process group prevents interactive TTY stop signals and ensures startup-file background descendants are terminated on completion, failure, output overflow (64 KiB) or timeout (5s), falling back to the inherited PATH on error.

Verification

• Ran cargo nextest run -p maka-desktop-shell --locked (unit tests and open_directly integration tests covering login-shell PATH import, non-leakage of other shell variables, background descendant cleanup, TERM/COLORTERM/MAKA_SKIP_SHELL_ENV=1 skip paths, non-zero exit fallback and output-flood bounding; verified new tests fail before the change and pass with it).
• Ran cargo clippy -p maka-desktop-shell --all-targets --no-deps -- -D warnings, just fmt-check, just licenses, node scripts/rust/dependencies.mjs generate and node scripts/rust/notices.mjs generate.
• Exercised Maka.app/Contents/MacOS/maka-desktop-shell under a stripped LaunchServices-equivalent environment (PATH=/usr/bin:/bin:/usr/sbin:/sbin, no TERM/COLORTERM, real /bin/zsh with noisy .zshrc banner) and confirmed the spawned maka launcher resolved /Users/yuhan/.local/bin/agy, /Users/yuhan/.local/bin/codex and /opt/homebrew/bin/claude.
• Did not run Linux GTK desktop tests or unrelated workspace crates locally; left to CI.

AI use

Select exactly one:

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Tool(s) and scope: Antigravity diagnosed the LaunchServices PATH root cause, implemented products/maka/desktop-shell/src/login_path.rs, updated main.rs, tests and desktop-shell READMEs, and ran local verification.

Checklist

• Tests cover the change and fail without it
• Format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — described under Summary above
• No