Add render export adapter contract

workplans/MKTT-WP-0020-render-export-adapter-contract.md

@@ -3,10 +3,10 @@ id: MKTT-WP-0020
 type: workplan
 title: "Render Export Adapter Contract"
 domain: markitect
-status: todo
+status: done
 owner: markitect-tool
 topic_slug: markitect
-planning_priority: P2
+planning_priority: complete
 planning_order: 150
 depends_on_workplans:
   - MKTT-WP-0013
@@ -55,11 +55,29 @@ renderer-specific sources. The two directions must stay separate now that
 
 Concrete Quarkdown integration belongs in `markitect-quarkdown`.
 
+## Implementation Summary - 2026-05-15
+
+Implemented the contract-only render/export adapter layer:
+
+- `RenderExportAdapterDescriptor`, `RenderExportAdapterRegistry`, and optional
+  package discovery through `markitect_tool.render_export_adapters`.
+- `RenderExportRequest`, `RenderExportResult`, `RenderArtifact`, and
+  `RenderProvenance` envelopes.
+- Built-in deterministic `render.fake` adapter for contract tests.
+- Capability and safety diagnostics for filesystem, network, external process,
+  native renderer dependency, assisted generation, and publication side-effect
+  boundaries.
+- Extension catalog descriptors for `render.export-registry` and `render.fake`.
+- Docs, fixture, public API exports, generated API reference, and tests.
+
+No real renderer, Quarkdown invocation, external process, or filesystem-writing
+publication behavior was added to `markitect-tool`.
+
 ## P20.1 - Define render adapter descriptors
 
 ```task
 id: MKTT-WP-0020-T001
-status: todo
+status: done
 priority: high
 state_hub_task_id: "5b52b196-a7f5-4e4f-abc6-972febdc2638"
 ```
@@ -86,7 +104,7 @@ registry tests.
 
 ```task
 id: MKTT-WP-0020-T002
-status: todo
+status: done
 priority: high
 state_hub_task_id: "3d43b168-7e55-4885-ae17-fcea262f2641"
 ```
@@ -108,7 +126,7 @@ Output: serializable models, round-trip tests, and docs.
 
 ```task
 id: MKTT-WP-0020-T003
-status: todo
+status: done
 priority: high
 state_hub_task_id: "45748ad7-131c-4b75-9720-6958fde93208"
 ```
@@ -130,7 +148,7 @@ Output: fake adapter, tests, and examples.
 
 ```task
 id: MKTT-WP-0020-T004
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "50aa8f00-eeba-495d-9d45-089f855fc3bd"
 ```
@@ -154,7 +172,7 @@ Output: capability constants, blocked-operation diagnostics, and tests.
 
 ```task
 id: MKTT-WP-0020-T005
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "173a75d0-d82c-4dcb-9ced-eb73e9438db2"
 ```