[Streams] Transfer retention tab to Kibana Management

[SoniaSanzV]

Summary

• Transfer ownership of Streams_app retention-related to Kibana Management via CODEOWNERS (data_management/stream_detail_lifecycle folder). Shared methods already moved in [Streams] Move helpers and format_size_unit to utils folder #262550
• Transfer ownership (review routing) of Streams retention-related backend areas to Kibana Management via CODEOWNERS: internal failure-store routes and library, internal ILM lifecycle routes, and ilm_policies / ilm_phases (+ tests).
• Isolate failure-store route support code in server/lib/streams/failure_store/ so that surface is easier to own and move later without dragging unrelated stream_crud code.
• No intentional change to product behavior or public APIs.

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)

[flash1293]

The code changes look good to me, but I'm not sure whether it's enough actually. @CoenWarmer you recently did this for the streams vs sigevents code, I think this change will still ping the onboarding team on every change in that area, right?

Approving for now because that's what we discussed and it's a good step, but still.

[SoniaSanzV]

The code changes look good to me, but I'm not sure whether it's enough actually. @CoenWarmer you recently did this for the streams vs sigevents code, I think this change will still ping the onboarding team on every change in that area, right?

Approving for now because that's what we discussed and it's a good step, but still.

As far as I know, CODEOWNERS works on a “last match wins” basis: for any given file, GitHub evaluates all matching patterns and the last matching rule in the file is the one that applies. So if I add a more specific ownership rule below a broader one (e.g., an override for .../stream_detail_lifecycle/** below a general Streams rule), the override should be valid and should take precedence for files under that subtree.

But waiting for @CoenWarmer for confirm in case I missed something

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 0bc25bc

Failed CI Steps

• FTR Configs #52
• FTR Configs #109

Test Failures

• [job] [logs] FTR Configs #52 / Entity Analytics - Risk Score Maintainer @ess @serverless @serverlessQA Risk Score Maintainer Task Lifecycle with maintainer test logs data @skipInServerlessMKI resumes producing additional scores after stop and restart when triggered

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
streamsApp	1842	1841	-1

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
streams	107	108	+1

Async chunks

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

id	before	after	diff
streamsApp	2.0MB	2.0MB	+13.0B

Page load bundle

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

id	before	after	diff
streams	13.7KB	13.7KB	+56.0B

Unknown metric groups

API count

id	before	after	diff
streams	110	111	+1

History

• 💔 Build #429761 failed 970bb47
• 💛 Build #427993 was flaky 30eb482
• 💛 Build #427401 was flaky b33af3e

cc @SoniaSanzV