fix: prevent date-stamped model names from false no-prefill detection

The regex now limits the minor version capture to 1-2 digits so
names like claude-opus-4-20250514 are not misclassified as 4.20250514.
Added tests for date-stamped and Bedrock-style model IDs.

Co-Authored-By: João <joao@crewai.com>

lib/crewai/src/crewai/llm.py

@@ -2295,7 +2295,7 @@ class LLM(BaseLLM):
         # Fallback heuristic for model names not in the litellm registry
         model_lower = (self.model or "").lower()
         if "claude" in model_lower:
-            match = re.search(r"claude.*?(\d+)[.-](\d+)", model_lower)
+            match = re.search(r"claude.*?(\d+)[.-](\d{1,2})(?!\d)", model_lower)
             if match:
                 major, minor = int(match.group(1)), int(match.group(2))
                 if (major == 4 and minor >= 6) or major >= 5:

lib/crewai/src/crewai/llms/providers/anthropic/completion.py

@@ -1838,7 +1838,7 @@ class AnthropicCompletion(BaseLLM):
         assistant prefill.
         """
         model_lower = self.model.lower()
-        match = re.search(r"claude.*?(\d+)[.-](\d+)", model_lower)
+        match = re.search(r"claude.*?(\d+)[.-](\d{1,2})(?!\d)", model_lower)
         if match:
             major, minor = int(match.group(1)), int(match.group(2))
             if (major == 4 and minor >= 6) or major >= 5:

lib/crewai/tests/agents/test_claude_opus_4_7_support.py

@@ -73,6 +73,17 @@ class TestAnthropicPrefillDetection:
         llm = self._make_anthropic_llm("claude-5-0-opus")
         assert llm.supports_assistant_prefill() is False
 
+    def test_date_stamped_claude_4_not_falsely_flagged(self):
+        """claude-opus-4-20250514 should NOT be treated as 4.20250514."""
+        llm = self._make_anthropic_llm("claude-opus-4-20250514")
+        assert llm.supports_assistant_prefill() is True
+
+    def test_bedrock_date_stamped_model(self):
+        """Bedrock-style IDs like claude-opus-4-20250514-v1:0 must not
+        be misclassified."""
+        llm = self._make_anthropic_llm("claude-opus-4-20250514-v1:0")
+        assert llm.supports_assistant_prefill() is True
+
 
 # ---------------------------------------------------------------------------
 # AnthropicCompletion temperature dropping