fix(react): render array params as list[T] in tools template

Map JSON Schema 'array' type to 'list[T]' for clearer Python-style
type hints in the tool descriptions sent to the model.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vilsonrodrigues

src/msgflux/generation/reasoning/react.py

@@ -35,9 +35,19 @@
 to assist with the user query. Don't make assumptions about what values
 to plug into functions. Here are the available tools:
 
+{%- macro render_type(spec) -%}
+{%- if spec.get('type') == 'array' and spec.get('items') -%}
+list[{{ spec['items'].get('type', 'unknown') }}]
+{%- elif spec.get('type') == 'array' -%}
+list
+{%- else -%}
+{{ spec.get('type', 'unknown') }}
+{%- endif -%}
+{%- endmacro -%}
+
 {%- macro render_properties(properties, required, indent=0) -%}
 {%- for arg, spec in properties.items() %}
-{{ "  " * indent }}- {{ arg }} ({{ spec.get('type', 'unknown') }}
+{{ "  " * indent }}- {{ arg }} ({{ render_type(spec) }}
 {%- if arg in required %}, required{% endif %})
 {%- if spec.get('description') %}
 {{ "  " * (indent + 1) }}{{ spec['description'] }}