feat(gemini): apply default safety settings across request translators

internal/translator/gemini/common/safety.go

@@ -0,0 +1,47 @@
+package common
+
+import (
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+)
+
+// DefaultSafetySettings returns the default Gemini safety configuration we attach to requests.
+func DefaultSafetySettings() []map[string]string {
+	return []map[string]string{
+		{
+			"category":  "HARM_CATEGORY_HARASSMENT",
+			"threshold": "OFF",
+		},
+		{
+			"category":  "HARM_CATEGORY_HATE_SPEECH",
+			"threshold": "OFF",
+		},
+		{
+			"category":  "HARM_CATEGORY_SEXUALLY_EXPLICIT",
+			"threshold": "OFF",
+		},
+		{
+			"category":  "HARM_CATEGORY_DANGEROUS_CONTENT",
+			"threshold": "OFF",
+		},
+		{
+			"category":  "HARM_CATEGORY_CIVIC_INTEGRITY",
+			"threshold": "BLOCK_NONE",
+		},
+	}
+}
+
+// AttachDefaultSafetySettings ensures the default safety settings are present when absent.
+// The caller must provide the target JSON path (e.g. "safetySettings" or "request.safetySettings").
+func AttachDefaultSafetySettings(rawJSON []byte, path string) []byte {
+	if gjson.GetBytes(rawJSON, path).Exists() {
+		return rawJSON
+	}
+
+	out, err := sjson.SetBytes(rawJSON, path, DefaultSafetySettings())
+	if err != nil {
+		return rawJSON
+	}
+
+	return out
+}