fix: detect Claude/Codex when launched from GUI (stripped PATH)

[NovakPAai]

Problem

When the desktop app is launched from Finder/Dock/Spotlight on macOS, the process inherits a minimal PATH (/usr/bin:/bin:/usr/sbin:/sbin) that omits user bin dirs like ~/.local/bin, ~/.npm-global/bin, nvm/fnm shims, and Homebrew — where CLIs such as claude and codex are installed.

src/agents-detect.js resolves claude/codex purely via which() over process.env.PATH. So a GUI launch detects only agents that ship as a .app bundle (Cursor via appBundle) and misses Claude Code and Codex entirely — even though their history is present and the terminal-launched CLI (codbash run) detects all of them.

Reproduced on a real machine:

# GUI-stripped PATH:
detected: cursor
# after fix:
detected: claude(path), codex(path), cursor(app-bundle)

Fix

New src/shell-path.js: at startup, when process.env.PATH contains no bin/shims directory under the user's home (the tell-tale of a Finder-stripped PATH), probe the user's login shell ($SHELL -i -l -c) for its real PATH and merge in the missing directories. Wired into bin/cli.js before any command runs.

• No-op when launched from a terminal — if PATH already has user bin dirs, no shell is spawned (zero added latency for CLI use).
• Opt-out: CODBASH_NO_PATH_REPAIR=1 skips the probe entirely. CODBASH_DEBUG=1 logs decisions.
• Sentinel-delimited capture so shell-integration banners can't corrupt the PATH; control-char entries (incl. TAB/DEL) are filtered; existing entries keep priority (new dirs appended, never shadowing system binaries).
• Time-boxed probe (4s, killSignal: SIGKILL) so a slow/SIGTERM-ignoring rc file can't wedge startup.
• Fixes both detection and in-process agent launching, generically for every PATH-detected agent (qwen, opencode, kilo, …).
• Windows is skipped (its GUI PATH isn't stripped this way). Zero new dependencies.

Acceptance criteria

• Happy path — GUI-stripped PATH, claude/codex in ~/.local/bin & ~/.npm-global/bin → both detected after startup.
• Terminal no-op — PATH already contains user bin dirs → no shell spawned, PATH unchanged.
• Negative — login-shell probe fails (bad $SHELL / hung rc / no sentinel) → error logged, existing PATH preserved, startup continues.
• Edge — captured entries with control chars / duplicate whitespace variants are dropped; append-after-system precedence preserved.
• Safety — CODBASH_NO_PATH_REPAIR=1 and win32 short-circuit before any spawn.

Test plan

• test/shell-path.test.js — 15 cases (gate logic incl. false-negative guard, merge/dedup, control-char + TAB/DEL filtering, whitespace dedup, precedence assertion, idempotency, win32 skip, opt-out, capture-failure, empty capture, process.env mutation)
• Full suite green: 202 passed / 0 failed / 1 pre-existing skip (node --test test/*.test.js)
• E2E: agents-detect under PATH=/usr/bin:/bin:/usr/sbin:/sbin goes cursor → claude, codex, cursor
• node -c syntax check on all touched files
• Passed code-review + security-review (no CRITICAL/HIGH remaining; all MEDIUM/LOW findings addressed)

Review notes

Went through a code review and a security review. No injection vector (fixed printf script, args array, no shell:true); the probe mirrors the same trust surface as opening a terminal (a compromised rc file already runs on any terminal open) and is now opt-out-able. All MEDIUM/LOW findings from both reviews are fixed in the second commit.

[vakovalskii]

Thanks for the thorough PR — the diagnosis is spot on: the desktop app spawns the server child inheriting the stripped GUI PATH (desktop/main.js), and agents-detect.js resolves CLIs by walking process.env.PATH, so Claude/Codex were being missed. Repairing PATH in bin/cli.js before detection is the right layer. I like that it's a true no-op from a terminal, opt-out-able (CODBASH_NO_PATH_REPAIR), and injection-free (args array, fixed script, no shell:true). Tests cover the tricky branches and pass against current main. LGTM — merging!