feat: enhance child edit and view components with improved form handling and validation

- Added `requireDirty` prop to `EntityEditForm` for dirty state management.
- Updated `ChildEditView` to handle initial data loading and image selection more robustly.
- Refactored `ChildView` to remove unused reward dialog logic and prevent API calls in child mode.
- Improved type definitions for form fields and initial data in `ChildEditView`.
- Enhanced error handling in form submissions across components.
- Implemented cross-tab logout synchronization on password reset in the auth store.
- Added tests for login and entity edit form functionalities to ensure proper behavior.
- Introduced global fetch interceptor for handling unauthorized responses.
- Documented password reset flow and its implications on session management.

frontend/vue-app/src/components/auth/ParentPinSetup.vue

@@ -39,6 +39,7 @@
       <p>Enter a new 4–6 digit Parent PIN. This will be required for parent access.</p>
       <input
         v-model="pin"
+        @input="handlePinInput"
         maxlength="6"
         inputmode="numeric"
         pattern="\d*"
@@ -47,6 +48,7 @@
       />
       <input
         v-model="pin2"
+        @input="handlePin2Input"
         maxlength="6"
         inputmode="numeric"
         pattern="\d*"
@@ -92,6 +94,16 @@ const isPinValid = computed(() => {
   return /^\d{4,6}$/.test(p1) && /^\d{4,6}$/.test(p2) && p1 === p2
 })
 
+function handlePinInput(event: Event) {
+  const target = event.target as HTMLInputElement
+  pin.value = target.value.replace(/\D/g, '').slice(0, 6)
+}
+
+function handlePin2Input(event: Event) {
+  const target = event.target as HTMLInputElement
+  pin2.value = target.value.replace(/\D/g, '').slice(0, 6)
+}
+
 async function requestCode() {
   error.value = ''
   info.value = ''