fix(circles): protect primary circle from rename in update_circle (v0.7.5)

Adds isFirstFamily check to update_circle — mirrors the same guard
already present in delete_circle. Attempting to rename the primary
circle now returns a clear error instead of silently renaming it.

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

README.md

@@ -2,7 +2,7 @@
 
 MCP server for [Family Wall](https://www.familywall.com) -- read and manage your family's circles, lists, tasks, and recipes directly from Claude.
 
-## Features (v0.7.4)
+## Features (v0.7.5)
 
 ### Read
 
@@ -31,7 +31,7 @@ MCP server for [Family Wall](https://www.familywall.com) -- read and manage your
 - `update_recipe` -- update any field of an existing recipe (partial update — omitted fields unchanged)
 - `delete_recipe` -- permanently delete a recipe (only own recipes)
 - `create_circle` -- create a new Family Wall circle (group)
-- `update_circle` -- rename a circle (server capitalises first letter; only name is changeable via API)
+- `update_circle` -- rename a circle (server capitalises first letter; only name is changeable via API; primary circle is protected)
 - `delete_circle` -- permanently delete a circle and all its content (primary circle is protected)
 - `add_member_to_circle` -- invite a person to a circle by e-mail (for new Family Wall users only; existing accounts require in-app invitation)