Use uuid matchers in search MV13 rollback fixtures (#271196)

## Summary

- Updates the `search` rollback fixtures for model version 13
(`10.13.0.json`) to use `{ "$match": "uuid" }` for Discover session tab
IDs instead of hardcoded UUIDs.
- MV13 tab IDs are generated via `uuidv5(savedObjectId, …)` during
migration, but rollback tests bulk-create documents without fixed IDs,
so the tab ID changes on every CI run and caused false fixture
mismatches on unrelated PRs.
- Adds a **Saved object fixtures** section to `.github/CODEOWNERS`,
assigning each `__fixtures__/<type>/` folder to the team that owns the
corresponding registered SO type (derived from the registering plugin's
`kibana.jsonc` owner or more specific CODEOWNERS paths).

## Test plan

- [x] `node scripts/check_changes.ts`
- [ ] CI: **Check changes in Saved Objects** rollback tests for `search`
pass when MV13 is in scope

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Davis McPhee <davismcphee@hotmail.com>

Author: 3 people

.github/CODEOWNERS

@@ -1407,6 +1407,46 @@ src/platform/plugins/private/ftr_apis/server/routes/task_manager @elastic/respon
 x-pack/platform/test/serverless/api_integration/test_suites/platform_security @elastic/kibana-security
 /src/platform/test/functional/apps/management @elastic/kibana-management
 
+# Saved object fixtures
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/action @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/alert @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/alerting_action_policy @elastic/rna-project-team
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/alerting_rule_template @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/api_key_pending_invalidation @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/api_key_to_invalidate @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/cases @elastic/kibana-cases
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/connector_token @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/data_connector @elastic/kibana-core
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/data_stream-config @elastic/integration-experience
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/entity-analytics-monitoring-entity-source @elastic/security-entity-analytics
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/entity-engine-descriptor-v2 @elastic/core-analysis
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/entity-store-global-state @elastic/core-analysis
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/epm-packages @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/fleet-agent-policies @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/fleet-cloud-connector @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/fleet-package-policies @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/gap_auto_fill_scheduler @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/ingest-agent-policies @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/ingest-outputs @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/ingest-package-policies @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/ingest_manager_settings @elastic/fleet
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/integration-config @elastic/integration-experience
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/maintenance-window @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/markdown @elastic/kibana-presentation
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/old-type-no-migrations @elastic/kibana-core
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/old-type-with-migrations @elastic/kibana-core
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/osquery-pack @elastic/security-defend-workflows
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/osquery-saved-query @elastic/security-defend-workflows
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/person-so-type @elastic/kibana-core
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/product-doc-install-status @elastic/appex-ai-infra
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/search @elastic/kibana-data-discovery
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/search-session @elastic/kibana-data-discovery
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/security-rule @elastic/security-detection-rule-management
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/stream-prompts @elastic/obs-onboarding-team @elastic/obs-sig-events-team
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/task @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/uiam_api_keys_provisioning_status @elastic/response-ops
+/packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/watchlist-entity-source @elastic/security-entity-analytics
+
 # Data Discovery
 /x-pack/platform/test/api_integration/services/data_view_api.ts @elastic/kibana-data-discovery
 /src/platform/test/functional/page_objects/unified_field_list.ts @elastic/kibana-data-discovery

packages/kbn-check-saved-objects-cli/src/migrations/__fixtures__/search/10.13.0.json

@@ -55,7 +55,7 @@
       "description": "Fixture saved search used for modelVersion migration checks",
       "tabs": [
         {
-          "id": "ed668b76-545d-5729-94c1-2eabade8ae48",
+          "id": { "$match": "uuid" },
           "label": "Untitled",
           "attributes": {
             "columns": ["@timestamp", "message"],
@@ -96,7 +96,7 @@
       "description": "",
       "tabs": [
         {
-          "id": "8a7dda1f-2493-44dd-a0e9-7c6557d02f3a",
+          "id": { "$match": "uuid" },
           "label": "Untitled",
           "attributes": {
             "columns": [],