GTM API / Retry mass-action items

Re-enter FAILED items of a mass action AT their current_step: completed steps never run again, their step_log entries and minted objects stay. Target EXACTLY ONE of sid (ma_im_…) or filter (both or neither: 422 sid_xor_filter_required); the filter arm is not parent-scoped, so pass mass_action_sid unless you mean every run. Per item: status pending, retry_count++, the error, timings and wait_reason cleared; parents settle again when drained. Only failed items match (retried_count 0 is not an error), 10 retries each at most, never an item of a deleted run or a cancelled one: by sid 422 retry_limit_exceeded and 409 cancelled_cannot_retry, by filter left alone. A send is never sent again blind: one failed send_unconfirmed or item_timeout is asked about under its key first; one with no key stays failed (left_unconfirmed_count) until a person checks the channel and retries it by sid with resend_unverified. Contract: - MCP tool retry_mass_action_items, registry package mcp.orchestration/mass_action_items, mount orchestration.mass_actions. - Operation action, response envelope action. - Flags: dangerous: the MCP layer gates it behind a preview/commit token, and the effect cannot be undone through this API; mass action: this verb's own request accepts a filter or targets[] set, which the owning service drains.