Add migration to backfill token_status for vulnerabilities in ES

What does this MR do and why?

Add migration to backfill token_status in vulnerabilities

bundle exec ruby scripts/elastic-migration backfill_token_status_in_vulnerabilities

References

Issue: Backfill migration for token_status field (#572848 - closed)

Mapping MR: - !203119 (merged)

Population MR: - !204042 (merged)

Screenshots or screen recordings

	Before	After
25_36
25_37

How to set up and validate locally

0. Follow the ES installation instructions first.

https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/main/doc/howto/elasticsearch.md?ref_type=heads

1. Apply temporary patch

Rollback schema version in the Vulnerability ES reference:

diff --git a/ee/lib/search/elastic/references/vulnerability.rb b/ee/lib/search/elastic/references/vulnerability.rb
index 6703054034811f..1f6d0f61066238 100644
--- a/ee/lib/search/elastic/references/vulnerability.rb
+++ b/ee/lib/search/elastic/references/vulnerability.rb
@@ -7,7 +7,7 @@ class Vulnerability < Reference
         include Search::Elastic::Concerns::DatabaseReference
         include ::Gitlab::Utils::StrongMemoize
 
-        SCHEMA_VERSION = 25_37
+        SCHEMA_VERSION = 25_36
         DOC_TYPE = 'vulnerability'
         INDEX_NAME = 'vulnerabilities'
 

---

2. Re-index vulnerabilities at old schema

GITLAB_SIMULATE_SAAS=1 bundle exec rails console

Vulnerabilities::Read.find_each do |v|
  Elastic::ProcessBookkeepingService.track!(
    Search::Elastic::References::Vulnerability.new(
      v.vulnerability_id,
      "group_#{v.project.namespace.root_ancestor.id}"
    )
  )
end

Elastic::ProcessBookkeepingService.new.execute # run until [0,0]

---

3. Verify schema before migration

• Docs on 2536 (expected >0):

curl -s "http://localhost:9200/gitlab-development-vulnerabilities/_count?pretty" \
  -H "Content-Type: application/json" \
  -d '{"query": {"term": {"schema_version": 2536}}}'

• Docs on 2537 (expected = 0):

curl -s "http://localhost:9200/gitlab-development-vulnerabilities/_count?pretty" \
  -H "Content-Type: application/json" \
  -d '{"query": {"term": {"schema_version": 2537}}}'

---

4. Restore schema and run migration

• Reset schema back to 25_37
• Restart console and jobs:

GITLAB_SIMULATE_SAAS=1 bundle exec rails console
gdk rails-background-jobs

• Run migration and bookkeeping:

Elastic::DataMigrationService[20251001130713].migrate
Elastic::ProcessInitialBookkeepingService.new.execute

---

5. Verify schema after migration

Repeat the same count queries as in step 3.

Expected:

• All docs are on 2537
• Count for 2536 is 0

MR acceptance checklist

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