refactor(evidence_capsule): Phase B language-advantage pass — dichotomy wave (allocation-free size sum)

src/rust/evidence_capsule/src/lib.rs

@@ -81,9 +81,16 @@ pub fn pack(claims: &[Json], contradictions: &[Json], limits: &[Json], raw_ref:
 }
 
 pub fn size(capsule: &Json) -> i64 {
-    as_list(capsule.get("claims")).len() as i64
-        + as_list(capsule.get("contradictions")).len() as i64
-        + as_list(capsule.get("limits")).len() as i64
+    // Phase B (language advantage): one pass over the three slot keys —
+    // the iterator sum never materializes the three intermediate Vec
+    // clones the naive port would build.
+    ["claims", "contradictions", "limits"]
+        .iter()
+        .map(|k| match capsule.get(k) {
+            Some(Json::Arr(xs)) => xs.len() as i64,
+            _ => 0,
+        })
+        .sum()
 }
 
 pub fn unpack(capsule: &Json) -> Json {