[b/r] Remove flowchart legend

The legend adds visual clutter without enough benefit. The colors
are self-explanatory from context.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: stuggi

docs/dev/backup-restore/backup-restore-controller-design.md

@@ -743,16 +743,7 @@ flowchart TD
 
     EnableIHA --> End([Restore Complete])
 
-    subgraph Legend[" "]
-        direction LR
-        L1[OADP Restore] ~~~ L2[Manual] ~~~ L3[Wait] ~~~ L4[Ready]
-        style L1 fill:#E1F5FE,font-size:11px
-        style L2 fill:#FFE4B5,font-size:11px
-        style L3 fill:#87CEEB,font-size:11px
-        style L4 fill:#90EE90,font-size:11px
-    end
-
-    style RestorePVC fill:#E1F5FE
+style RestorePVC fill:#E1F5FE
     style RestoreFoundation fill:#E1F5FE
     style RestoreInfra fill:#E1F5FE
     style RestoreCtlPlane fill:#E1F5FE