feat: synchronize recipe completion controls

Fixes #5\nRefs #1, #2

README.md

@@ -2,7 +2,10 @@
 
 A MagicMirror module that displays recipes from a read-only Nextcloud public
 share. It includes a phone-friendly control page for choosing a recipe,
-adjusting its number of portions, and entering or leaving recipe mode.
+adjusting its number of portions, marking ingredients and steps complete, and
+entering or leaving recipe mode. Completion marks are shared with the mirror
+and retained until a different recipe is selected, so a recipe can be resumed
+after exiting recipe mode.
 
 Create a public share for the folder configured as your Nextcloud Cookbook
 recipe directory. Read-only permission is sufficient. Copy the public share
@@ -30,6 +33,11 @@ the best use of the available screen while keeping all recipe content visible.
 The recipe title, timing metadata, yield, and QR controller remain at fixed
 sizes.
 
+When portions change, the display shows both the selected yield and the
+recipe's original yield. Ingredients without a leading quantity are marked in
+yellow because they cannot be scaled; unsupported or imprecise numeric scaling
+is marked in red.
+
 The configured `position` controls where the QR controller appears during the
 normal MagicMirror layout. When a recipe is activated, the module displays a
 fixed full-screen overlay regardless of that region. Exiting recipe mode