fix: upgrade marvin>=3.2.0 to fix contact-extractor crash

Marvin 3.0.x/3.1.x are incompatible with pydantic-ai>=1.56.0 (required
for CVE-2026-25580). The Agent class lost the `_deprecated_result_tool_name`
attribute in pydantic-ai 1.56+, causing AttributeError in marvin's
streaming.py when using `run_async()` with union result_type.

Upgrade to marvin>=3.2.0 which is compatible with modern pydantic-ai.

Assisted-By: Claude (Anthropic AI) <noreply@anthropic.com>
Signed-off-by: Paolo Dettori <dettori@us.ibm.com>

Author: pdettori

a2a/a2a_contact_extractor/pyproject.toml

@@ -5,7 +5,7 @@ description = "Currency conversion using A2A and Marvin"
 readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
-    "marvin>=3.0.0", 
+    "marvin>=3.2.0",  # 3.0.x/3.1.x incompatible with pydantic-ai>=1.56
     "a2a-sdk>=0.2.5,<0.4.0",
     "urllib3>=2.6.3",   # Indirect; prevents CVE-2025-66418
     "python-multipart>=0.0.22", # Indirect; prevents CVE-2026-24486