feat(workflow): support template-bound workflow versions

[Cynthia-0203]

What this PR does / Why we need it:

Support strongly binding Workflow V4 instances to workflow templates.

What is changed and how it works?

• Add workflow_template_version to store template version snapshots.
• Add template binding metadata to WorkflowV4.
• Store frontend-provided delta_patches for template-bound workflows.
• Render bound workflows from template version + patches at read time.

Does this PR introduce a user-facing change?

• API change
• database schema change
• upgrade assistant change
• change in non-functional attributes such as efficiency or availability
• fix of a previous issue

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This change is