Two hardening items from argus's review of #2374:
1. PR state check at submission:
- Add `pr_is_open(repo, pr)` to forge/pr_merge.rs using
`repo_get_pull_request` + `StateType` — early error if the PR is
already closed or merged instead of queuing a card that fails later
- Call it in `submit_merge_config_pr` before fetching the head sha
2. Atomic fetched_sha INSERT:
- Add `fetched_sha: Option<&str>` to `Approvals::submit_kind` so
the sha can be included in the INSERT rather than a follow-up UPDATE
- MergeConfigPr already knows the sha before inserting the row
(pr_head_sha runs first) → pass `Some(&sha)`, drop the separate
`set_fetched_sha` call → truly atomic
- ApplyCommit still needs two writes (sha resolved by git_fetch_to_tag
after the row exists) → pass `None`, `set_fetched_sha` unchanged
- All other callers (InitConfig, Spawn, UpdateMetaInputs,
SchedulePrompt) pass `None` — no behavioural change
- Add `fetched_sha_in_insert_is_readable_via_get` test covering the
MergeConfigPr path
MergeConfigPr approvals had a fully-implemented approve handler
(run_merge_config_pr, ff_push_to_main, mark_pr_merged) and dashboard
display, but no way to submit one. An agent with the `approvals` tool
group calling request_merge_config_pr(agent, pr_number) is the missing
piece.
What this adds:
- RequestMergeConfigPr variant in hive-sh4re AgentRequest + ToolGroup::Approvals
- submit_merge_config_pr: fetches PR head sha (the drift-gate reviewed sha),
queues a MergeConfigPr row, sets fetched_sha, emits approval_added with
pr_number so the dashboard card links to the forge PR
- handle_request_merge_config_pr: topology (require_descendant) +
tool-group (require_group(approvals)) guards before submit
- socket_server/mod.rs: dispatch arm for RequestMergeConfigPr
- hive-ag3nt MCP tool: request_merge_config_pr with full description
- docs/tools/lifecycle.md: documents the new tool + boundary table row
Unlike submit_apply_commit, no flake pre-flight at submission time (eval-
verify happens at approval time inside run_merge_config_pr, same as the
rest of the merge pipeline). Applied repo must already exist (guard added
with a clear error message pointing at request_apply_commit for first-spawn).
