stem95su: scheduled Drive->site sync CronJob (every 10m)

CronJob stem95su-gdrive-sync (*/10) mounts the content PVC RW and
rclone-syncs the read-only Drive folder "claude" (stem claude/files) onto
it (rclone/rclone:1.74.3, scope=drive.readonly, empty-source guard +
--max-delete 25). ESO ExternalSecret stem95su-rclone <- Vault
secret/stem95su. Requires the GCP OAuth app published to Production or the
refresh token expires ~weekly.

Lands the gdrive-sync stack on master (it had landed on a feature branch
by accident on the shared devvm checkout).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.claude/commands/update-knowledge.md

@@ -1,12 +0,0 @@
-# Update Knowledge Base
-
-Update the .claude/CLAUDE.md knowledge file with new learnings.
-
-Add or update information based on recent discoveries about:
-- Service versions
-- Infrastructure patterns
-- Important configurations
-- Useful commands
-- Troubleshooting notes
-
-Context to add: $ARGUMENTS