[Feature]: Model Provider Support

Please select the area the issue is related to

AI Workspace, Platform API

Please select the aspect the issue is related to

Aspect/UI (Frontend layouts, components, styling), Aspect/API (API backends, definitions, contracts, interfaces, OpenAPI)

Suggested Feature

Currently, we cannot add the relevant model providers and the available model list from an LLM provider template. In the AI Workspace, the model providers and the list of available models shown for an LLM provider are rendered/hardcoded on the frontend, not sourced from backend data.

An improvement should be made to allow users to define a template's model providers and their available model lists when creating or editing an LLM provider template, persist them in the llm_provider_templates table, and automatically populate them when a provider is created from that template. The solution must support both single-model-provider and multi-model-provider templates.

Related Issues

https://github.com/wso2/api-platform/issues/2495

Steps to Verify

• Design Document — A detailed design document has been created and reviewed, covering architecture, data flow, and edge cases.
• Design Mail — A design summary email has been sent to relevant stakeholders for awareness and feedback.
• Code Review — All code changes have been peer-reviewed and approved according to the project's review standards.
• Testing Complete — Adequate unit, integration, and/or end-to-end tests have been written and are passing.
• Documentation Review — User-facing and/or developer documentation has been updated to reflect the new feature and reviewed.
• Feature Complete — The feature is fully implemented, all checklist items above are done, and it is ready for release.

Start by reviewing related issue #2495 and tracing the AI Workspace and Platform API flows for creating and editing LLM provider templates. Investigate the llm_provider_templates table and the provider-creation path, then define how single- and multi-model-provider templates should persist and populate model data; done means the design, implementation, tests, and documentation checklist are complete.