feat(DATAGO-130052): Add model dependents functionality with endpoint for retrieving dependent agents

[cyrus2281]

What is the purpose of this change?

Add support for safely deleting model configurations by providing a mechanism to identify and handle agent dependencies before deletion. This helps prevent broken deployments when a model configuration is removed while agents are still using it.

How was this change implemented?

High-level approach:

• Added a ModelDependentsHandler interface that enterprise code can implement
• Created endpoints for model-dependent agent management:
  • GET /models/{alias}/dependents to list agents using a model
  • Enhanced DELETE /models/{alias} to automatically undeploy dependent agents
• Added a registration mechanism for enterprise-specific model dependent handling
• Implemented comprehensive unit tests for the new functionality

Key commits:

• feat: Add model dependents handling and endpoint for retrieving dependent agents
• test: Add unit tests for model dependents endpoint and handler functionality

Key Design Decisions

• Used a handler pattern with dependency injection to allow enterprise-specific code to handle model dependencies
• Default implementation is a no-op to maintain backward compatibility in community edition
• Enterprise implementation is loaded dynamically via import to maintain separation between editions

How was this change tested?

• Manual testing: Verified model dependents API returns empty list in community edition
• Unit tests: Added comprehensive tests for model dependents endpoint and handler functionality
• Integration tests: Not applicable for this change
• Known limitations: Enterprise-specific functionality is tested separately in the enterprise repo

Is there anything the reviewers should focus on/be aware of?

The enterprise implementation details are handled in a separate repository, this PR only adds the interface and community version.

[github-actions]

✅ FOSSA Guard: Licensing (SolaceLabs_solace-agent-mesh) • PASSED

Compared against main (4a355dab7572521050d2f26f9dae2b267ccddcbf) • 0 new, 6 total (6 in base)

Scan Report | View Details in FOSSA

[github-actions]

✅ FOSSA Guard: Vulnerability (SolaceLabs_solace-agent-mesh) • PASSED

Compared against main (4a355dab7572521050d2f26f9dae2b267ccddcbf) • 0 new, 3 total (3 in base)

Scan Report | View Details in FOSSA

[sonarqube-solacecloud]

Quality Gate passed

Issues
3 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube