Check source function annotations and unify managed function identity

crates/objects/src/code.rs

@@ -17,6 +17,14 @@ pub struct CodeLayout {
     pub names: Vec<String>,
 }
 
+/// Source declaration metadata, separate from executable slot layout.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SourceSignature {
+    pub parameters: Vec<String>,
+    pub return_type: String,
+    pub method_owner: Option<String>,
+}
+
 #[derive(Debug, Clone)]
 pub struct EndorCode {
     bytecode: Vec<u8>,
@@ -27,6 +35,7 @@ pub struct EndorCode {
     name: String,
     filename: String,
     first_line: usize,
+    signature: Option<SourceSignature>,
 }
 
 impl EndorCode {
@@ -73,9 +82,30 @@ impl EndorCode {
             name: "<code>".into(),
             filename: "<endor>".into(),
             first_line: 1,
+            signature: None,
         })
     }
 
+    pub fn with_source_signature(mut self, signature: SourceSignature) -> Result<Self, VmError> {
+        if signature.parameters.len() != self.parameters().len()
+            || signature.return_type.is_empty()
+            || signature.parameters.iter().any(String::is_empty)
+            || signature
+                .method_owner
+                .as_ref()
+                .is_some_and(String::is_empty)
+        {
+            return Err(VmError::InvalidArgument(
+                "source signature does not match code parameters",
+            ));
+        }
+        self.signature = Some(signature);
+        Ok(self)
+    }
+    pub fn source_signature(&self) -> Option<&SourceSignature> {
+        self.signature.as_ref()
+    }
+
     pub fn with_location(
         mut self,
         name: impl Into<String>,