Configure Agent Build resources and credential bindings

[SaladDay]

Agent creation and editing now configure the applicable Build resources in one form, including versioned Skills and tool integrations, model credentials, environment templates, and existing communication connector settings. Inline resource creation returns to the preserved Agent draft; resource bindings save atomically and execution freezes the selected Skill bytes and model credentials privately. Existing marketplace pins survive deprecation/unpublishing without gaining access to later private revisions. Cloning preserves resources and uses the existing credential-selection flow; dedicated connector writes target only an existing Agent being edited.

The change stays in Parsar. Following the product decision, protocol-defined features missing from Core remain explicitly reserved: hosted MCP, additional Skills with an Environment Template, and Plugins. These combinations must not silently run with missing configuration. Product requirements and the Core boundary are recorded in the linked product document.

Validation:

• Full make check passed on Linux; final frontend adjustments passed make check-web and touched-file ESLint.
• Actual MiniMax Code execution read a random marker from the saved Skill using the Agent-selected credential while the Provider default key was invalid.
• Browser verification covered inline Skill creation, preserved draft, existing integration editor, Agent creation/editing/refresh, marketplace resource selection, and cloning with the same pinned Skill.
• Migration and API checks verify model credential kinds work without development fixtures for both personal and shared credentials.
• Store/runtime regression tests cover atomic rollback, version/pinning preservation, encrypted snapshots, archive integrity and unsupported combinations.

Deployment: merged as 72ab4d37; deployed to mx with product backup. Product/Core health and HTTPS 200 verified. Core was unchanged. Final independent review found no blocking issues; all required CI checks passed. The final production browser check was blocked by the existing untrusted TLS certificate; local UI acceptance passed.