feat: compare accountability update deltas

docs/accountability-root-manifest.md

@@ -45,6 +45,12 @@ Ownership review schema:
 schemas/accountability-ownership-review.schema.yaml
 ```
 
+Update delta schema:
+
+```text
+schemas/accountability-update-delta.schema.yaml
+```
+
 ## Required Sections
 
 - `netkingdom`: root id, name, and king actor.
@@ -142,3 +148,19 @@ railiance-fabric review-identity identity:repository:example-repo \
 Reviewer decisions are keyed by stable identity key. Later rescans apply the
 latest decision for that key, so ordinary evidence refreshes do not lose
 reviewed ownership choices.
+
+## Update Deltas
+
+To compare the current run with previous identity and ownership-review outputs:
+
+```bash
+railiance-fabric discover-roots \
+  --delta \
+  --previous-identity-projection previous-identities.json \
+  --previous-ownership-review previous-ownership.json
+```
+
+The delta separates candidate graph node changes, candidate graph edge changes,
+ownership changes, containment changes, review-state changes, and blocker
+changes. When `summary.promotion_needed` is `false`, the update loop can skip
+promotion because the durable evidence produced no meaningful Fabric change.

docs/financial-fabric-operator-guide.md

@@ -76,6 +76,14 @@ railiance-fabric review-identity <stable-key> \
   --fabric-id fabric.railiance.primary
 ```
 
+To compare a new run with saved review outputs:
+
+```bash
+railiance-fabric discover-roots --delta \
+  --previous-identity-projection previous-identities.json \
+  --previous-ownership-review previous-ownership.json
+```
+
 The financial export must satisfy these invariants:
 
 - every accepted node has resolvable ownership;