feat: add native tool calling support to OpenAI-compatible providers

[roomote]

Summary

This PR adds native tool calling support to all providers that extend BaseOpenAiCompatibleProvider, ensuring they can utilize the tool calling functionality that was recently added to the base class.

Changes

FeatherlessHandler

• Updated getCompletionParams() to accept and pass through metadata parameter
• Added tool support to DeepSeek-R1 path with proper tool call accumulation
• Ensured tools are passed to both R1 and non-R1 model paths

ZAiHandler

• Added tools and tool_choice parameters to the createStream() method
• Tools are now properly passed through when creating chat completions

GroqHandler

• Added tool call accumulation logic to createMessage()
• Properly handles streaming tool calls and yields them when finish_reason is 'tool_calls'

Testing

All existing tests pass:

• ✅ featherless.spec.ts (13 tests)
• ✅ groq.spec.ts (10 tests)
• ✅ zai.spec.ts (24 tests)

Impact

This change enables native tool calling for:

• Featherless (including DeepSeek-R1 models)
• Z AI (all models)
• Groq (all models)

All changes are backward compatible and don't affect providers that don't use tools.

[roomote]

Rooviewer   See task on Roo Cloud

Re-review complete. The new commit enables supportsNativeTools for 8 additional Groq models. All changes are consistent with the existing implementation and no issues were found.

Previous reviews

• 7a6ee82: Review #1

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}