feat: introduce custom provider example and remove redundant debug logs

- Added `examples/custom-provider/main.go` showcasing custom executor and translator integration using the SDK.
- Removed redundant debug logs from translator modules to enhance code cleanliness.
- Updated SDK documentation with new usage and advanced examples.
- Expanded the management API with new endpoints, including request logging and GPT-5 Codex features.

internal/translator/gemini-cli/gemini/gemini-cli_gemini_request.go

@@ -32,7 +32,6 @@ import (
 // Returns:
 //   - []byte: The transformed request data in Gemini API format
 func ConvertGeminiRequestToGeminiCLI(_ string, inputRawJSON []byte, _ bool) []byte {
-	log.Debug("ConvertGeminiRequestToGeminiCLI")
 	rawJSON := bytes.Clone(inputRawJSON)
 	template := ""
 	template = `{"project":"","request":{},"model":""}`