feat: add grok-4.20-beta-0309-non-reasoning model

Author: Kamilbenkirane

src/celeste/modalities/text/providers/xai/models.py

@@ -103,6 +103,21 @@
             TextParameter.OUTPUT_SCHEMA: Schema(),
         },
     ),
+    Model(
+        id="grok-4.20-beta-0309-non-reasoning",
+        provider=Provider.XAI,
+        display_name="Grok 4.20 Beta 0309 Non Reasoning",
+        operations={Modality.TEXT: {Operation.GENERATE}},
+        streaming=True,
+        parameter_constraints={
+            Parameter.TEMPERATURE: Range(min=0.0, max=2.0),
+            Parameter.MAX_TOKENS: Range(min=1, max=30000),
+            TextParameter.WEB_SEARCH: Bool(),
+            TextParameter.X_SEARCH: Bool(),
+            TextParameter.CODE_EXECUTION: Bool(),
+            TextParameter.OUTPUT_SCHEMA: Schema(),
+        },
+    ),
     Model(
         id="grok-3-mini",
         provider=Provider.XAI,