run directory semantics, status interpretation, and practical troubleshooting steps

Run Artifacts and Debugging

Every task execution creates a run directory:

.ship/task/<taskId>/<timestamp>/

Core artifacts

File	Purpose
`input.md`	definition snapshot for this run
`output.md`	output body (`agent`: successfully delivered channel text; `script`: script output)
`result.md`	human-readable summary
`run.json`	final status payload
`run-progress.json`	live progress snapshot
`dialogue.md`	multi-round summary (`agent`)
`dialogue.json`	structured round records (`agent`)
`messages.jsonl`	execution context message stream
`error.md`	failure summary

resultStatus=invalid
- usually output too short
executionStatus=failure
- usually script execution failure, agent runtime failure, or failed chat_send delivery
Task skipped (already running)
- overlap trigger skipped by per-task serial guard
one-shot when=time:... no longer auto-runs
- expected behavior after execution: paused + @manual