CLI and API polish

src/markitect_tool/extension/builtins.py

@@ -12,6 +12,8 @@ def builtin_extension_registry() -> ExtensionRegistry:
 
     registry = default_query_engine_registry().extension_registry()
     for descriptor in _processor_descriptors() + [
+        _extension_catalog_descriptor(),
+        _generated_docs_descriptor(),
         _local_sqlite_backend_descriptor(),
         _workflow_engine_descriptor(),
         _runtime_context_descriptor(),
@@ -25,6 +27,51 @@ def builtin_extension_registry() -> ExtensionRegistry:
     return registry
 
 
+def _extension_catalog_descriptor() -> ExtensionDescriptor:
+    return ExtensionDescriptor(
+        id="extension.catalog",
+        kind="extension-registry",
+        summary="Inspectable catalog of built-in extension descriptors and CLI affordances.",
+        capabilities=[
+            ProcessingCapability(id="extensions", kind="inspect"),
+            ProcessingCapability(id="cli", kind="inspect"),
+        ],
+        safety={"reads_files": False, "writes_files": False, "network": False},
+        input_contract="Built-in ExtensionRegistry",
+        output_contract="ExtensionDescriptor catalog | CliCommandSpec list",
+        diagnostics_namespace="extension",
+        provenance_prefix="extension.catalog",
+        cli={
+            "commands": [
+                "mkt extension list",
+                "mkt extension inspect",
+                "mkt extension commands",
+            ]
+        },
+        docs=["docs/internal-extension-framework.md"],
+    )
+
+
+def _generated_docs_descriptor() -> ExtensionDescriptor:
+    return ExtensionDescriptor(
+        id="docs.generated-reference",
+        kind="documentation",
+        summary="Generated CLI and API reference documentation from live command and API surfaces.",
+        capabilities=[
+            ProcessingCapability(id="docs", kind="generate"),
+            ProcessingCapability(id="cli", kind="inspect"),
+            ProcessingCapability(id="api", kind="inspect"),
+        ],
+        safety={"reads_files": False, "writes_files": True, "network": False},
+        input_contract="Click command tree | markitect_tool.__all__",
+        output_contract="Markdown reference document",
+        diagnostics_namespace="docs",
+        provenance_prefix="docs.generated_reference",
+        cli={"commands": ["mkt docs cli", "mkt docs api"]},
+        docs=["docs/cli-reference.md", "docs/api-reference.md"],
+    )
+
+
 def _processor_descriptors() -> list[ExtensionDescriptor]:
     return [
         ExtensionDescriptor(