Enhanced usecase example weave tangle for later workflows

workplans/MKTT-WP-0006-cache-backend-architecture-core.md

@@ -12,8 +12,10 @@ depends_on_workplans:
   - MKTT-WP-0004
 depends_on_tasks:
   - MKTT-WP-0003-T005
+related_workplans:
+  - MKTT-WP-0010
 created: "2026-05-03"
-updated: "2026-05-03"
+updated: "2026-05-04"
 state_hub_workstream_id: "0c585f8a-5c7e-4c89-b785-5b0089180256"
 ---
 
@@ -31,6 +33,7 @@ Research and architecture are captured in:
 
 - `docs/research-lab-cache-backend-research.md`
 - `docs/cache-backend-architecture-blueprint.md`
+- `docs/content-reference-literate-workflow-research.md`
 
 ## Decision
 
@@ -38,6 +41,11 @@ Do not start this before the current deterministic transform/composition slice
 has enough shape to show what cache invalidation must preserve. Start it before
 WP-0003 P3.7 caching becomes implementation work.
 
+Keep the backend fabric open for `MKTT-WP-0010` content-unit identities,
+reference graphs, processor provenance, and weave/tangle source maps. Those
+features do not need to be implemented here, but the capability model should not
+make them awkward later.
+
 ## P6.1 - Define backend capability model
 
 ```task
@@ -70,6 +78,9 @@ state_hub_task_id: "5debc135-908a-47ed-ba15-564610970e38"
 Specify content-addressed document snapshots keyed by source content hash,
 parser version, parse options, and contract version where relevant.
 
+Include a placeholder for stable content-unit identities and dependency edges so
+references/chunks can be cached and invalidated later.
+
 ## P6.3 - Define backend interfaces
 
 ```task
@@ -82,6 +93,9 @@ state_hub_task_id: "a3e37112-1197-4f6f-8de8-7b3067ef060e"
 Add protocol classes for snapshot backends, index backends, query adapters,
 context package registries, and access policy gateways.
 
+Leave room for processor-result stores, reference graph adapters, and source-map
+or provenance adapters.
+
 ## P6.4 - Implement local backend registry
 
 ```task