feat(ai): add DeepSeek provider support

[bulutmuf]

What does this PR do?

This PR introduces DeepSeek as a first-class AI provider within Dokploy. It strictly adheres to the existing AI provider abstraction and design patterns, seamlessly integrating DeepSeek into the current infrastructure without requiring any UI overhauls.

Key Changes

• Provider Registration: Added DeepSeek to the standard AI_PROVIDERS list (using https://api.deepseek.com), making it directly accessible from the AI Settings dropdown.
• SDK Integration: Integrated the official Vercel AI SDK @ai-sdk/deepseek package.
• Middleware/Interceptor Adapter: Implemented a fetch interceptor middleware within select-ai-provider.ts. This seamlessly normalizes the payload right before the HTTP request leaves the server, transparently addressing DeepSeek's custom parameter requirements (such as hinking and
  easoning_effort overrides) without bleeding into the generic AI UI layer.
• Type Safety & Reliability: Ensured TypeScript compatibility and strictly maintained existing architecture without causing any unrelated refactoring.

This empowers users to instantly select DeepSeek from the models list, input their API key, and begin deploying applications with advanced reasoning capabilities natively.

Testing Performed

• Locally verified successful integration and provider configuration in the settings UI.
• Validated server-side compilation, dependencies, and API request handling.

Greptile Summary

Adds DeepSeek as a selectable AI provider and completes its integration:

• Registers the DeepSeek endpoint and model discovery behavior.
• Uses the existing OpenAI-compatible provider abstraction with request normalization.
• Updates server package exports for extension-bearing ESM subpaths.
• Aligns Zod dependencies and the workspace lockfile.

Confidence Score: 5/5

The PR appears safe to merge.

The extension-bearing wildcard export fixes the previously reported ESM loading failure, and DeepSeek now uses the existing OpenAI-compatible provider protocol rather than the incompatible provider implementation; no blocking failure remains.

_{Reviews (2): Last reviewed commit: "fix(ai): resolve provider protocol misma..." | Re-trigger Greptile}