Extension framework optimization

tests/test_extension_processing_model.py

@@ -33,6 +33,13 @@ def test_processing_request_serializes_context_and_cache_key():
         options={"format": "json"},
         capabilities=[ProcessingCapability(id="ast", description="Read parsed AST")],
     ).cache_key
+    assert request.cache_key != ProcessingRequest(
+        operation="query.selector",
+        input={"selector": "sections[heading=Decision]"},
+        context=ProcessingContext(source_path=Path("other.md")),
+        options={"format": "json"},
+        capabilities=[ProcessingCapability(id="ast", description="Read parsed AST")],
+    ).cache_key
 
 
 def test_processing_result_validity_provenance_and_trace():
@@ -58,6 +65,21 @@ def test_processing_result_validity_provenance_and_trace():
     assert data["trace"][0]["metadata"]["engine"] == "selector"
 
 
+def test_processing_result_with_trace_preserves_envelope_fields():
+    result = ProcessingResult(
+        output={"count": 1},
+        dependencies=["doc.md"],
+        metadata={"engine": "selector"},
+    )
+
+    traced = result.with_trace(ProcessingTrace(event="query.done"))
+
+    assert traced.output == result.output
+    assert traced.dependencies == ["doc.md"]
+    assert traced.metadata == {"engine": "selector"}
+    assert traced.trace[0].event == "query.done"
+
+
 def test_processing_result_from_error_normalizes_diagnostics():
     result = ProcessingResult.from_error(
         code="extension.missing_dependency",