feat: gemini 3.0 pro preview added (as default gemini pro model)

refactor: code cleanup

conf/gemini_models.json

@@ -26,11 +26,11 @@
   },
   "models": [
     {
-      "model_name": "gemini-2.5-pro",
-      "friendly_name": "Gemini (Pro 2.5)",
+      "model_name": "gemini-3-pro-preview",
+      "friendly_name": "Gemini Pro 3.0 Preview",
       "aliases": [
         "pro",
-        "gemini pro",
+        "gemini3",
         "gemini-pro"
       ],
       "intelligence_score": 18,
@@ -48,6 +48,27 @@
       "allow_code_generation": true,
       "max_image_size_mb": 32.0
     },
+    {
+      "model_name": "gemini-2.5-pro",
+      "friendly_name": "Gemini Pro 2.5",
+      "aliases": [
+        "gemini-pro-2.5"
+      ],
+      "intelligence_score": 18,
+      "description": "Older Model. 1M context - Complex problems, architecture, deep analysis",
+      "context_window": 1048576,
+      "max_output_tokens": 65536,
+      "max_thinking_tokens": 32768,
+      "supports_extended_thinking": true,
+      "supports_system_prompts": true,
+      "supports_streaming": true,
+      "supports_function_calling": true,
+      "supports_json_mode": true,
+      "supports_images": true,
+      "supports_temperature": true,
+      "allow_code_generation": true,
+      "max_image_size_mb": 32.0
+    },
     {
       "model_name": "gemini-2.0-flash",
       "friendly_name": "Gemini (Flash 2.0)",