Specify protected circuit groups

docs/spec/07-implementation-phases-todo.md

@@ -496,7 +496,41 @@ Acceptance criteria:
 - restoring an older state does not delete intervening history
 - concurrent stale commands cannot silently overwrite newer project state
 
-## Phase 13: External Model Round-Trip
+## Phase 13: Distribution Board Components and Protection Groups
+
+Goal:
+
+Extend the circuit list into the structural basis of a tabular single-line
+diagram before defining Revit parameter exchange.
+
+Detailed specification:
+
+- `docs/spec/09-distribution-board-components-and-protection-groups.md`
+
+Delivery:
+
+- add typed protection-device catalogs and defaults
+- evolve sections into repeatable category-specific circuit groups
+- add fixed, group and auxiliary distribution-board components
+- give every new circuit one explicit protection device
+- implement nested BMK generation, same-category group moves and explicit
+  collision-safe group renumbering
+- preserve all new state through commands, snapshots, transfer and persistent
+  Undo/Redo
+- project the header, groups and auxiliary footer in the spreadsheet editor
+
+Acceptance criteria:
+
+- new boards contain the main switch, surge protective device and three default
+  groups
+- all circuits and components have list-wide unique BMKs
+- circuit reordering keeps identifiers while cross-group moves assign the next
+  target-group identifier
+- destructive group operations are confirmed, atomic and fully undoable
+- existing supported project data migrates without silently changing BMKs or
+  protection selections
+
+## Phase 14: External Model Round-Trip
 
 Goal:
 
@@ -521,7 +555,7 @@ Acceptance criteria:
 
 PostgreSQL should be introduced when shared multi-user operation, background jobs or operational scale justify it. External-object count alone does not require an immediate migration.
 
-## Phase 14: Documentation and Collaboration Handoff
+## Phase 15: Documentation and Collaboration Handoff
 
 Goal: