Summary

• Keep terminal tabs alive after blocking scripts (run/archive/delete) complete so the user can inspect output
• Show failure alerts with a "View Terminal" button for all blocking script kinds
• Simplify blocking script completion by removing intermediate state tracking (blockingScriptCommandFinished, blockingScriptLastCommandExitCode) in favor of a single completeBlockingScript helper that fires on COMMAND_FINISHED instead of waiting for SHOW_CHILD_EXITED
• Report launch failures (file system errors, tab creation) with exit code 1 instead of nil so the reducer surfaces an alert

Test plan

• Trigger a run/archive/delete script and verify the terminal tab stays open after completion
• Trigger a failing script and verify the alert shows with a "View Terminal" button that navigates to the correct tab
• Re-run a blocking script of the same kind while one is in progress — old tab should close, only the new one fires completion
• Close a blocking script tab manually — should be treated as cancellation (no alert)
• Ctrl+C a running script — should report the signal-based exit code in the alert
• All unit tests pass (make test)