Extensible canonical internal processing refactoring

tests/test_extension_processing_model.py

@@ -0,0 +1,75 @@
+from pathlib import Path
+
+from markitect_tool.extension import (
+    ProcessingCapability,
+    ProcessingContext,
+    ProcessingProvenance,
+    ProcessingRequest,
+    ProcessingResult,
+    ProcessingTrace,
+)
+
+
+def test_processing_request_serializes_context_and_cache_key():
+    request = ProcessingRequest(
+        operation="query.selector",
+        input={"selector": "sections[heading=Decision]"},
+        context=ProcessingContext(root=Path("/workspace"), caller="cli"),
+        options={"format": "json"},
+        capabilities=[ProcessingCapability(id="ast", description="Read parsed AST")],
+    )
+
+    data = request.to_dict()
+
+    assert data["operation"] == "query.selector"
+    assert data["context"]["root"] == "/workspace"
+    assert data["context"]["caller"] == "cli"
+    assert data["capabilities"][0]["id"] == "ast"
+    assert request.cache_key.startswith("processing:")
+    assert request.cache_key == ProcessingRequest(
+        operation="query.selector",
+        input={"selector": "sections[heading=Decision]"},
+        context=ProcessingContext(root=Path("/other")),
+        options={"format": "json"},
+        capabilities=[ProcessingCapability(id="ast", description="Read parsed AST")],
+    ).cache_key
+
+
+def test_processing_result_validity_provenance_and_trace():
+    result = ProcessingResult(
+        output={"count": 1},
+        provenance=[
+            ProcessingProvenance(
+                operation="query.selector",
+                source_path="doc.md",
+                content_hash="sha256:abc",
+                dependencies=["doc.md"],
+            )
+        ],
+        trace=[ProcessingTrace(event="query.start", metadata={"engine": "selector"})],
+    )
+
+    data = result.to_dict()
+
+    assert result.valid
+    assert data["valid"] is True
+    assert data["output"]["count"] == 1
+    assert data["provenance"][0]["operation"] == "query.selector"
+    assert data["trace"][0]["metadata"]["engine"] == "selector"
+
+
+def test_processing_result_from_error_normalizes_diagnostics():
+    result = ProcessingResult.from_error(
+        code="extension.missing_dependency",
+        message="Install optional dependency.",
+        source_path="doc.md",
+        line=3,
+        details={"dependency": "jsonpath-ng"},
+    )
+
+    data = result.to_dict()
+
+    assert not result.valid
+    assert data["diagnostics"][0]["severity"] == "error"
+    assert data["diagnostics"][0]["source"]["path"] == "doc.md"
+    assert data["diagnostics"][0]["details"]["dependency"] == "jsonpath-ng"