agentpr/watchpr already propagated command errors to a non-zero exit, but
that behaviour had no regression coverage and the root command was not
constructible outside main(). watchpr also fired a spurious conflict alert
because Gitea computes mergeability asynchronously and can briefly report
mergeable=false right after a push. The docs additionally printed the
AppRole role_id literal UUID.
- Extract newRootCmd() in both cmd/agentpr and cmd/watchpr so main() only
runs Execute and exits non-zero on error; add tests asserting Execute
returns an error for a bad PR ref / malformed --repo / no args.
- Debounce mergeability loss in MeaningfulChange: only alert when
mergeable=false persists across two consecutive polls (both prev and cur
false, still open); update the table test for one-poll-false (benign),
false-persisting (alert), and recovered false->true (benign).
- Refer to AGENT_APPROLE_ROLE_ID by env var in README.md/AGENTS.md without
printing the literal role_id; keep the code default and env override.
