Stop a loop whose backend CLI is not on PATH, and say so

[scgopi]

What changes

When a loop's backend CLI (claude, copilot, codex, opencode) can't be found, GraphCode now stops the loop and shows a dialog instead of leaving a dead session that reads running — or, when the pane reported the exit, succeeded.

claude is not on your PATH
“Hello” was stopped. GraphCode couldn't find claude, the Claude Code command-line tool, so the loop was stopped instead of left running without an agent. Loops start their agent from a login shell (/bin/zsh -i -l): install Claude Code, or add the folder containing claude to PATH in ~/.zshrc or ~/.zprofile, then restart the loop.

How it's detected

The daemon resolves the executable the way launches do — /bin/zsh -i -l -c 'whence -p -- <exe>' in a PTY (ProviderPath). whence -p rather than command -v, because the launch execs the agent and an alias wouldn't survive that. Bounded at 15s; an undecided probe never stops a loop. Found answers are cached briefly; missing ones never are.

Where	Covers
After every GraphStore.ensureSession	Daemon launches (ZmxSessionLauncher)
Pane exit report (nodeCheckApproved)	App-terminal launches (GhosttyTerminalView) — the exit no longer resolves the loop
Presence reading with exit code 127	Any session no launch checked

Remote projects are skipped — their PATH belongs to another machine.

Stop, dialog, restart

• The node goes to stopped with LoopNode.launchFailure, which carries the executable, backend, and time. Older apps decode snapshots unchanged. The card shows the reason, and the loop's memory records it.
• The app raises the dialog when a snapshot carries a failure it hasn't shown yet. Failures a project already had when it first loaded stay on their cards, with no dialog at launch.
• Restart Session is now allowed for a loop stopped this way. It clears the failure and launches again. A daemon restart doesn't relaunch it.
• A key pressed on the dead pane no longer deletes such a loop.

Gate (worktree, private DerivedData)

Step	Result
xcodebuild test -scheme graphcode	exit=0 — 1730 tests in 183 suites passed, including 12 new in ProviderNotOnPathTests
xcodebuild build -scheme graphcode-cli / graphcoded	exit=0 / exit=0
swiftlint lint errors	0
swift format lint --strict	exit=0
scripts/cli-smoke.sh (fresh SwiftPM build)	exit=0, 5/5 verbs
Isolated daemon, claude off the login shell's PATH, goal loop on Claude Code	running → stopped; memory: "stopped: claude is not on your PATH — …"; launchFailure persisted