feat: add Claude Sonnet 4.5 and update alias configuration

- Added anthropic/claude-sonnet-4.5 with sonnet and sonnet4.5 aliases
- Updated sonnet alias to point to newest Sonnet 4.5 (was 4.1)
- Kept sonnet4.1 alias for backwards compatibility with Claude Sonnet 4.1
- All tests updated and passing 100%

conf/custom_models.json

@@ -50,6 +50,21 @@
     }
   },
   "models": [
+    {
+      "model_name": "anthropic/claude-sonnet-4.5",
+      "aliases": [
+        "sonnet",
+        "sonnet4.5"
+      ],
+      "context_window": 200000,
+      "max_output_tokens": 64000,
+      "supports_extended_thinking": false,
+      "supports_json_mode": false,
+      "supports_function_calling": false,
+      "supports_images": true,
+      "max_image_size_mb": 5.0,
+      "description": "Claude Opus 4.5 - Our most capable and intelligent model yet"
+    },
     {
       "model_name": "anthropic/claude-opus-4.1",
       "aliases": ["opus", "claude-opus"],
@@ -64,7 +79,7 @@
     },
     {
       "model_name": "anthropic/claude-sonnet-4.1",
-      "aliases": ["claude", "sonnet", "sonnet4.1", "claude-sonnet", "claude-4.1-sonnet", "claude-sonnet-4.1"],
+      "aliases": ["sonnet4.1"],
       "context_window": 200000,
       "max_output_tokens": 64000,
       "supports_extended_thinking": false,