fix(templates): pin db-related image tags

[cuisongliu]

Summary

• pin db/storage-related template image references to explicit tags
• keep KubeBlocks/database resource definitions unchanged
• keep each project in this batch scoped to a single PR

Projects: cloudreve, dify-1.13.3, dify-1.14.2, headscale, headscale-pg, influxdb, laf, n8n, reactive-resume, signoz, stirling-pdf, tailchat

Verification

• Ruby YAML parse for files without template condition expressions
• template-expression files n8n and stirling-pdf were diff-checked only because existing ${{ if(...) }} blocks are not plain YAML
• image reference scan for this batch reports no untagged, digest, or latest references
• git diff --check