fix(gemini): handle "[DONE]" chunk, trim "data:" prefix, and remove session_id from requests

- Adjusted stream handling to skip "[DONE]" chunks.
- Ensured "data:" prefix is trimmed for non-prefixed input in translation.
- Removed `session_id` from request bodies before processing.

sdk/translator/types.go

@@ -1,21 +1,34 @@
+// Package translator provides types and functions for converting chat requests and responses between different schemas.
 package translator
 
 import "context"
 
-// RequestTransform converts a request payload from one schema to another.
+// RequestTransform is a function type that converts a request payload from a source schema to a target schema.
+// It takes the model name, the raw JSON payload of the request, and a boolean indicating if the request is for a streaming response.
+// It returns the converted request payload as a byte slice.
 type RequestTransform func(model string, rawJSON []byte, stream bool) []byte
 
-// ResponseStreamTransform converts streaming responses between schemas.
+// ResponseStreamTransform is a function type that converts a streaming response from a source schema to a target schema.
+// It takes a context, the model name, the raw JSON of the original and converted requests, the raw JSON of the current response chunk, and an optional parameter.
+// It returns a slice of strings, where each string is a chunk of the converted streaming response.
 type ResponseStreamTransform func(ctx context.Context, model string, originalRequestRawJSON, requestRawJSON, rawJSON []byte, param *any) []string
 
-// ResponseNonStreamTransform converts non-stream responses between schemas.
+// ResponseNonStreamTransform is a function type that converts a non-streaming response from a source schema to a target schema.
+// It takes a context, the model name, the raw JSON of the original and converted requests, the raw JSON of the response, and an optional parameter.
+// It returns the converted response as a single string.
 type ResponseNonStreamTransform func(ctx context.Context, model string, originalRequestRawJSON, requestRawJSON, rawJSON []byte, param *any) string
 
+// ResponseTokenCountTransform is a function type that transforms a token count from a source format to a target format.
+// It takes a context and the token count as an int64, and returns the transformed token count as a string.
 type ResponseTokenCountTransform func(ctx context.Context, count int64) string
 
-// ResponseTransform groups streaming and non-streaming transforms.
+// ResponseTransform is a struct that groups together the functions for transforming streaming and non-streaming responses,
+// as well as token counts.
 type ResponseTransform struct {
-	Stream     ResponseStreamTransform
-	NonStream  ResponseNonStreamTransform
+	// Stream is the function for transforming streaming responses.
+	Stream ResponseStreamTransform
+	// NonStream is the function for transforming non-streaming responses.
+	NonStream ResponseNonStreamTransform
+	// TokenCount is the function for transforming token counts.
 	TokenCount ResponseTokenCountTransform
 }