Merge upstream/final-form into master

Incorporates WIP alternative measurement form (single select form with
multiple select actions) and readouts controller.

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

config/locales/en.yml

@@ -85,7 +85,7 @@ en:
     navigation: Measurements
     no_items: There are no measurements taken. You can Add some now.
     form:
-      select_quantity: select the measured quantities...
+      select_quantity: select the measured quantity...
     index:
       new_measurement: Add measurement
     create:
@@ -97,6 +97,7 @@ en:
   readouts:
     form:
       select_unit: ...
+      new_children: Children
   quantities:
     navigation: Quantities
     no_items: There are no configured quantities. You can Add some or Import from defaults.

config/routes.rb

@@ -4,6 +4,7 @@ Rails.application.routes.draw do
 
   resources :measurements
 
+
   resources :readouts, only: [:new] do
     collection {get 'new/:id/discard', action: :discard, as: :discard}
   end