[OPIK-5716] [BE] feat: create new blueprint from mask changes delta

[BorisTkachenko]

Details

Add a new endpoint to create a blueprint by applying a mask's changes on top of the latest blueprint for a project. The endpoint POST /blueprints/from-mask/projects/{project_id}/masks/{mask_id} fetches the mask's delta values and creates a new BLUEPRINT-type config through the existing updateConfig flow, which handles merging with the latest blueprint values.

Change checklist

• User facing
• Documentation update

Issues

• OPIK-5716

AI-WATERMARK

AI-WATERMARK: yes

• If yes:
  • Tools: Claude Code (Claude Opus 4.6)
  • Model(s): claude-opus-4-6
  • Scope: Full implementation - endpoint, service method, tests
  • Human verification: Code review pending

Testing

• 3 integration tests added in AgentConfigsResourceTest.CreateBlueprintFromMask:
  • Success: creates blueprint from mask, verifies merged config values (mask overrides + inherited values)
  • 404 when mask ID does not exist
  • 404 when no config exists for the project

Documentation

N/A - internal API endpoint

[github-actions]

Backend Tests - Integration Group 5

127 tests   127 ✅  2m 58s ⏱️
 30 suites    0 💤
 30 files      0 ❌

Results for commit 40a387f.

♻️ This comment has been updated with latest results.

[andrescrz]

Let's review the open comments, including Baz, before moving forward.