docs: clarify silent-drop behavior for typed AP schemas in if let Ok comment

"future-proofs" implied graceful handling; the comment now accurately notes
that a type mismatch silently drops the entry, same as the catch-all arm.

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

Author: charlie-zhang109

.generator/src/generator/templates/model_simple.j2

@@ -119,7 +119,8 @@ impl<'de> Deserialize<'de> for {{ name }} {
 
                 while let Some((k, v)) = map.next_entry::<String, serde_json::Value>()? {
                     {%- if additionalProperties != false and model.get("x-keep-typed-in-additional-properties") %}
-                    // from_value::<serde_json::Value> is infallible; the Ok guard future-proofs typed AP schemas.
+                    // from_value::<serde_json::Value> is infallible so Ok always fires;
+                    // for typed AP schemas a type mismatch silently drops the entry (same as the catch-all arm).
                     if let Ok(ap_value) = serde_json::from_value(v.clone()) {
                         additional_properties.insert(k.clone(), ap_value);
                     }