Add source attachment metadata compatibility

workplans/MKTF-WP-0003-source-attachment-manifest-compatibility.md

@@ -3,10 +3,10 @@ id: MKTF-WP-0003
 type: workplan
 title: "Source Attachment Manifest Compatibility"
 domain: markitect
-status: todo
+status: done
 owner: markitect-filter
 topic_slug: markitect
-planning_priority: P2
+planning_priority: complete
 planning_order: 30
 depends_on_workplans:
   - MKTF-WP-0001
@@ -56,11 +56,27 @@ render asset manifest.
 Those responsibilities belong to `markitect-tool` contracts,
 `markitect-quarkdown` render integration, or later runtime/publication systems.
 
+## Implementation Summary
+
+Completed as a read-side attachment metadata compatibility slice:
+
+- Added shared source attachment metadata helpers and exported
+  `markitect-filter.source-attachment.v1`.
+- EPUB3 read results now populate `NormalizedMarkdownDocument.attachments` for
+  package images, stylesheets, fonts, audio, and video with byte size, digest,
+  package path, manifest id, href, and render-manifest compatibility metadata.
+- PDF read results now populate attachments for embedded file streams and
+  signal-only image resources where the stdlib parser can detect them.
+- Unsupported EPUB resources, missing EPUB resources, PDF image signals, and
+  unreadable embedded files produce structured diagnostics.
+- Docs, handoff fixtures, adapter descriptors, README notes, and tests were
+  added without introducing renderer/export behavior.
+
 ## P3.1 - Align attachment metadata with Markitect source contracts
 
 ```task
 id: MKTF-WP-0003-T001
-status: todo
+status: done
 priority: high
 state_hub_task_id: "d119daca-8141-4662-8ad7-ce43ccd79044"
 ```
@@ -76,7 +92,7 @@ run with `markitect-tool` on `PYTHONPATH`.
 
 ```task
 id: MKTF-WP-0003-T002
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "ebcbf480-210d-46e7-a4e4-fbe7e9baa39a"
 ```
@@ -91,7 +107,7 @@ Output: EPUB3 attachment metadata, provenance, diagnostics, and fixtures.
 
 ```task
 id: MKTF-WP-0003-T003
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "d8b7b820-387f-4d45-bf22-296b227f917a"
 ```
@@ -108,7 +124,7 @@ Output: PDF metadata conventions, diagnostics, and tests.
 
 ```task
 id: MKTF-WP-0003-T004
-status: todo
+status: done
 priority: high
 state_hub_task_id: "ca539c01-c272-4635-8f60-86f870bbef0c"
 ```
@@ -128,7 +144,7 @@ Output: deterministic digest/provenance tests.
 
 ```task
 id: MKTF-WP-0003-T005
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "f2213a20-ce6f-4e16-9b9b-557b99f8b4d1"
 ```