feat(CUST-WP-0017): scope-analyst agent + SCOPE.md template + coverage

T01: copy agent-scope-analyst.md to the-custodian/agents/
T02: add scope.template, prepend @SCOPE.md to claude-md.template,
     update register_project.sh to write SCOPE.md stub on new registration,
     add scope-analyst row to TOOLS.md
T03: SCOPE.md for the-custodian itself
Workplan: CUST-WP-0017 registered in state-hub

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

scripts/register_project.sh

@@ -142,6 +142,15 @@ if [[ "$ADDITIONAL" != "--additional" ]]; then
         fi
     done
 
+    SCOPE_MD="$PROJECT_PATH/SCOPE.md"
+    if [[ ! -f "$SCOPE_MD" ]]; then
+        echo "==> Writing SCOPE.md stub ..."
+        render_template "$RULES_TEMPLATES_DIR/scope.template" > "$SCOPE_MD"
+        echo "    SCOPE.md written (stub — fill with scope-analyst agent)."
+    else
+        echo "==> SCOPE.md already exists — skipping."
+    fi
+
     if [[ -f "$CLAUDE_MD" ]]; then
         echo ""
         echo "==> CLAUDE.md already exists — appending @-import suggestion."