## Summary
Part of elastic#201807

**Strategy**:
This PR assumes that `switchToModelVersionAt` has done it’s job and all
SO type owners now use `modelVersions` instead of `migrations`.
It takes the approach of trusting that this is fine™

**Changes in this PR:**
- `switchToModelVersionAt` removed from all registered saved objects, so
their mapping hash had to be updated.
- Implements `globalSwitchToModelVersionAt` directly in `version_map`
- Updates logic to prioritize `modelVersions` over `migrations` in
`getLatestMappingsModelVersion`, that previously relied on
`switchToModelVersionAt` being set
- Updates unit tests to match the refactored logic
- Updates snapshots
- Adapts SO types registered in the **cases**, **SLO** and **encrypted
saved objects** plugins.
- Updates docs

**Risks**:
- Plugin developers disregard the deprecated status of `migrations` and
introduce new versions, which will not be BWC. Saved object type hash
changes will notify the core team for a code owner review. The core team
needs to investigate the related changes and provide feedback.

### Checklist

Check the PR satisfies following conditions.

Reviewers should verify this PR satisfies this list as well.

- [x]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…#219329)

# Backport

This will backport the following commits from `main` to `9.0`:
- [Removed switchToModelVersionAt from SO API definition
(#219029)](#219029)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT [{"author":{"name":"Christiane (Tina)
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PR assumes that `switchToModelVersionAt` has done it’s job and all\nSO
type owners now use `modelVersions` instead of `migrations`.\nIt takes
the approach of trusting that this is fine™\n\n**Changes in this
PR:**\n- `switchToModelVersionAt` removed from all registered saved
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BWC. Saved object type hash\nchanges will notify the core team for a
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changes and provide feedback.\n\n\n### Checklist\n\nCheck the PR
satisfies following conditions. \n\nReviewers should verify this PR
satisfies this list as well.\n\n-
[x]\n[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)\nwas
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PR assumes that `switchToModelVersionAt` has done it’s job and all\nSO
type owners now use `modelVersions` instead of `migrations`.\nIt takes
the approach of trusting that this is fine™\n\n**Changes in this
PR:**\n- `switchToModelVersionAt` removed from all registered saved
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`globalSwitchToModelVersionAt` directly in `version_map`\n- Updates
logic to prioritize `modelVersions` over `migrations`
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BWC. Saved object type hash\nchanges will notify the core team for a
code owner review. The core team\nneeds to investigate the related
changes and provide feedback.\n\n\n### Checklist\n\nCheck the PR
satisfies following conditions. \n\nReviewers should verify this PR
satisfies this list as well.\n\n-
[x]\n[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)\nwas
added for features that require explanation or tutorials\n- [x] [Unit or
functional\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\nwere
updated or added to match the most common scenarios\n- [x] The PR
description includes the appropriate Release Notes section,\nand the
correct `release_note:*` label is applied per
the\n[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)\n\n---------\n\nCo-authored-by:
Elastic Machine
<elasticmachine@users.noreply.github.com>\nCo-authored-by: kibanamachine
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switchToModelVersionAt from SO API definition (#219029)\n\n##
Summary\nPart of
https://github.com/elastic/kibana/issues/201807\n\n**Strategy**:\nThis
PR assumes that `switchToModelVersionAt` has done it’s job and all\nSO
type owners now use `modelVersions` instead of `migrations`.\nIt takes
the approach of trusting that this is fine™\n\n**Changes in this
PR:**\n- `switchToModelVersionAt` removed from all registered saved
objects, so\ntheir mapping hash had to be updated.\n- Implements
`globalSwitchToModelVersionAt` directly in `version_map`\n- Updates
logic to prioritize `modelVersions` over `migrations`
in\n`getLatestMappingsModelVersion`, that previously relied
on\n`switchToModelVersionAt` being set\n- Updates unit tests to match
the refactored logic\n- Updates snapshots\n- Adapts SO types registered
in the **cases**, **SLO** and **encrypted\nsaved objects** plugins.\n-
Updates docs\n\n**Risks**:\n- Plugin developers disregard the deprecated
status of `migrations` and\nintroduce new versions, which will not be
BWC. Saved object type hash\nchanges will notify the core team for a
code owner review. The core team\nneeds to investigate the related
changes and provide feedback.\n\n\n### Checklist\n\nCheck the PR
satisfies following conditions. \n\nReviewers should verify this PR
satisfies this list as well.\n\n-
[x]\n[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)\nwas
added for features that require explanation or tutorials\n- [x] [Unit or
functional\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\nwere
updated or added to match the most common scenarios\n- [x] The PR
description includes the appropriate Release Notes section,\nand the
correct `release_note:*` label is applied per
the\n[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)\n\n---------\n\nCo-authored-by:
Elastic Machine
<elasticmachine@users.noreply.github.com>\nCo-authored-by: kibanamachine
<42973632+kibanamachine@users.noreply.github.com>","sha":"19c017a111ff79155b2e7f94abe7601efd3d86c2"}}]}]
BACKPORT-->

---------

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…c#219029)"

This reverts commit 19c017a.

…" (#220063)

This reverts commit 19c017a.

## Summary


Reverts #219029 as it is causing SO Migration crashes in our QA
environment.

It can also be tested locally on `main`:

1. On a previous version (`git checkout deploy@1745820726`)
2. Start ES: `yarn es serverless --projectType es`
3. Start Kibana: `yarn start --serverless=es`
4. Wait for migrations to complete
5. Stop Kibana
6. Move back to `main`
7. Start Kibana: `yarn start --serverless=es`
8. Wait for the error

On `main`, we can see that Kibana fails to start with the fatal error:

```
 FATAL  Error: Unable to complete saved object migrations for the [.kibana_alerting_cases] index: Model version conflict: inconsistent higher/lower versions
```

In this branch, it starts successfully.

…" (#220059)

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…c#219029)" (elastic#220059)

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
(cherry picked from commit 75c0f95)

# Conflicts:
#	src/core/server/integration_tests/ci_checks/saved_objects/check_registered_types.test.ts

…219029)" (#220059) (#220259)

# Backport

This will backport the following commits from `main` to `9.0`:
- [Revert "Removed switchToModelVersionAt from SO API definition
(#219029)" (#220059)](#220059)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

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## Summary
Part of elastic#201807

**Strategy**:
This PR assumes that `switchToModelVersionAt` has done it’s job and all
SO type owners now use `modelVersions` instead of `migrations`.
It takes the approach of trusting that this is fine™

**Changes in this PR:**
- `switchToModelVersionAt` removed from all registered saved objects, so
their mapping hash had to be updated.
- Implements `globalSwitchToModelVersionAt` directly in `version_map`
- Updates logic to prioritize `modelVersions` over `migrations` in
`getLatestMappingsModelVersion`, that previously relied on
`switchToModelVersionAt` being set
- Updates unit tests to match the refactored logic
- Updates snapshots
- Adapts SO types registered in the **cases**, **SLO** and **encrypted
saved objects** plugins.
- Updates docs

**Risks**:
- Plugin developers disregard the deprecated status of `migrations` and
introduce new versions, which will not be BWC. Saved object type hash
changes will notify the core team for a code owner review. The core team
needs to investigate the related changes and provide feedback.


### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [x]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…c#219029)" (elastic#220059)

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…c#219029)" (elastic#220059)

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…20985)

## Summary

* Address #217145 - Put in place
a check to ensure we're upgrading from Kibana 8.18.0 or newer.
* Address #220521 - New attempt
at removing the `switchToModelVersionAt` property, inspired on
#219029.

The previous attempt caused a regression: index meta information started
storing _modelVersions_ that were older than the previously stored ones,
which were defaulting to 10.0.0 for SO types that did NOT define
`modelVersions`.

This was due to the removal of the applyTypeDefaults, which was ensuring
all SOs had the `switchToModelVersionAt` property set.

This flag was then used by
`src/core/packages/saved-objects/base-server-internal/src/model_version/version_map.ts`
to determine whether to use `modelVersions` or the legacy `migrations`
property in order to determine the latest model version for a given
type.

When removing the `switchToModelVersionAt` flag (and its default
backfill), the logic started defaulting to the latest `migrations`
version for those SO types that were not defining any `modelVersion`,
resulting in older versions that those stored in the SO indices. This
caused incident https://elasticco.atlassian.net/browse/INC-3818.

This regression has been shipped in 9.0.0 (the PR was
[backported](#219329)), so in top
of the cleanup, we now need to address
#220521 to ensure a smooth
transition _OnPrem => Serverless_.

---------

Co-authored-by: Christiane (Tina) Heiligers <christiane.heiligers@elastic.co>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

…astic#220985)

## Summary

* Address elastic#217145 - Put in place
a check to ensure we're upgrading from Kibana 8.18.0 or newer.
* Address elastic#220521 - New attempt
at removing the `switchToModelVersionAt` property, inspired on
elastic#219029.

The previous attempt caused a regression: index meta information started
storing _modelVersions_ that were older than the previously stored ones,
which were defaulting to 10.0.0 for SO types that did NOT define
`modelVersions`.

This was due to the removal of the applyTypeDefaults, which was ensuring
all SOs had the `switchToModelVersionAt` property set.

This flag was then used by
`src/core/packages/saved-objects/base-server-internal/src/model_version/version_map.ts`
to determine whether to use `modelVersions` or the legacy `migrations`
property in order to determine the latest model version for a given
type.

When removing the `switchToModelVersionAt` flag (and its default
backfill), the logic started defaulting to the latest `migrations`
version for those SO types that were not defining any `modelVersion`,
resulting in older versions that those stored in the SO indices. This
caused incident https://elasticco.atlassian.net/browse/INC-3818.

This regression has been shipped in 9.0.0 (the PR was
[backported](elastic#219329)), so in top
of the cleanup, we now need to address
elastic#220521 to ensure a smooth
transition _OnPrem => Serverless_.

---------

Co-authored-by: Christiane (Tina) Heiligers <christiane.heiligers@elastic.co>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>