Move the FIPS migration guide into the Migration nav area

esethna asked for this page to live within the migration area of the docs
nav rather than the deployment area, pointing at
administration-guide/manage/admin/migration.html.

Registers the page in that Migration hub's toctree and bullet list, and
removes its entry from the Server Deployment toctree so it no longer
appears under the deployment area of the nav.

The file itself stays at deployment-guide/server/fips-migration.rst,
mirroring how the MySQL-to-PostgreSQL migration is handled: that page also
lives under deployment-guide/ while its only toctree home is this Migration
hub, and deployment pages link to it inline. Keeping the file put also
preserves the relative cross-reference from containers/fips-stig.rst and
avoids putting container and Kubernetes mechanics under
administration-guide/onboard/, where the neighbouring pages are all about
migrating to Mattermost from another platform.

Grouped next to the PostgreSQL migration in the hub, since both are
infrastructure migrations rather than platform or data migrations.

The visible bullet on the Server Deployment planning page is retained as a
plain :doc: cross-reference, which creates no toctree membership. That
keeps the guide discoverable for admins browsing deployment docs, and
matches how deployment pages already link to the PostgreSQL migration.
Leaving the entry in both toctrees instead would have made this the
repository's fifth page referenced from multiple toctrees, which Sphinx
warns about and conf.py does not suppress.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: ewwollesen

source/administration-guide/manage/admin/migration.rst

@@ -11,6 +11,7 @@ Whether you’re migrating from another platform, upgrading your database, or us
    :titlesonly:
 
     Migrate from MySQL to PostgreSQL </deployment-guide/postgres-migration>
+    Migrate to FIPS-compliant images </deployment-guide/server/fips-migration>
     Server migration guide </administration-guide/onboard/migrating-to-mattermost>
     Migrate from Slack </administration-guide/onboard/migrate-from-slack>
     Migrate from Rocket.Chat </administration-guide/onboard/migrate-from-rocketchat>
@@ -20,6 +21,7 @@ Whether you’re migrating from another platform, upgrading your database, or us
     Migration announcement email template </administration-guide/onboard/migration-announcement-email>
 
 * :doc:`Migrate from MySQL to PostgreSQL </deployment-guide/postgres-migration>` - Learn how to migrate from MySQL to PostgreSQL.
+* :doc:`Migrate to FIPS-compliant images </deployment-guide/server/fips-migration>` - Learn how to switch an existing Docker or Kubernetes deployment to the FIPS-compliant Mattermost images.
 * :doc:`Server migration guide </administration-guide/onboard/migrating-to-mattermost>` - Learn about about migrating to Mattermost.
 * :doc:`Migrate from Slack </administration-guide/onboard/migrate-from-slack>` - Learn how to migrate from Slack to Mattermost.
 * :doc:`Migrate from Rocket.Chat </administration-guide/onboard/migrate-from-rocketchat>` - Learn how to migrate from Rocket.Chat to Mattermost.

source/deployment-guide/server/server-deployment-planning.rst

@@ -12,7 +12,6 @@ This section provides comprehensive guidance on deploying and managing your Matt
     Deploy with Kubernetes </deployment-guide/server/deploy-kubernetes>
     Deploy with Linux </deployment-guide/server/deploy-linux>
     Deploy with Containers </deployment-guide/server/deploy-containers>
-    Migrate to FIPS-compliant images </deployment-guide/server/fips-migration>
     Pre-authentication secrets </deployment-guide/server/pre-authentication-secrets>
     Deployment Solution Programs </deployment-guide/server/orchestration>