[Alerting v2] Split action policies APIs

[cnasikas]

Summary

Same as #277616, this PR splits the generic bulk action policy APIs into multiple bulk action APIs per operation. This makes the Rules and Action Policies APIs consistent with the same responses. It also aligns the response schema for the bulk alert action API.

Fixes: https://github.com/elastic/rna-program/issues/364
Fixes: https://github.com/elastic/rna-program/issues/352

Checklist

Check the PR satisfies following conditions.

Reviewers should verify this PR satisfies this list as well.

• Unit or functional tests were updated or added to match the most common scenarios

[infra-vault-gh-plugin-prod]

Pinging @elastic/response-ops (Team:ResponseOps)

[github-actions]

Reviewed the action-policy bulk API split. The server refactor (per-action by-ID endpoints, shared BulkResponse shape, canonical bulk-error mapping) and its unit + Scout coverage look solid. One concrete issue: the _bulk_action (alert actions) response contract change was not propagated to the alert-episodes UI consumer, which will break the bulk-action toasts. Flagged inline.

Generated by Claude Reviewer for #280238 · 600.1 AIC · ⌖ 11.8 AIC · ⊞ 4.6K

[cnasikas]

@elasticmachine merge upstream

[kibanamachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 7aba145
• Build duration: 61 mins

Failed CI Steps

• Scout Lane #10 - stateful-classic / default

Test Failures

• [job] [logs] Scout Lane #10 - stateful-classic / default / local-stateful-classic - Entity attachment cases – flyout add-to-case actions and Entities accordion - Entities accordion renders when entity attachments were added via API
• [job] [logs] Scout Lane #10 - stateful-classic / default / local-stateful-classic - Entity attachment cases – flyout add-to-case actions and Entities accordion - renders no Entities accordion when a case has no entity attachments

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
alertingVTwo	1.3MB	1.3MB	+1.4KB
securitySolution	13.6MB	13.6MB	+31.0B
total			+1.4KB

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
alertingVTwo	26.0KB	26.6KB	+603.0B
securitySolution	190.5KB	190.5KB	+8.0B
total			+611.0B

History

• 💛 Build #474428 was flaky d35e928
• 💔 Build #474029 failed 4cc6acc

cc @cnasikas