fix(signature-footer): save concrete template value instead of empty sentinel

Previously onTemplateReset and onCustomizeFooterTemplateChange used
footerTemplate:'' as a sentinel meaning 'use the inherited template'.
This sentinel relied on the value-computed hook to inject inheritedTemplate
at display time, but the emitted model value carried '' — which gets saved
to the user preference as-is.

On the next page load, if inheritedTemplate resolved to something different
(or to '' because no admin customization exists), the display and the
preference diverged, showing blank or the wrong value after reset.

Fix: make both operations save the concrete value:
- onTemplateReset now saves footerTemplate:props.inheritedTemplate so
  the preference stores the real inherited default explicitly.
- onCustomizeFooterTemplateChange (enable path) now seeds the template
  with the current display value (which already incorporates inheritedTemplate
  via the computed) so enabling customization never stores an empty template
  when an inherited default is available.

Signed-off-by: Vitor Mattos <[email protected]>

Author: vitormattos

src/views/Settings/PolicyWorkbench/settings/signature-footer/SignatureFooterRuleEditor.vue

@@ -213,6 +213,10 @@ const showResetTemplateButton = computed(() => {
 	}
 
 	const inheritedTemplate = (props.inheritedTemplate ?? '').trim()
+	if (inheritedTemplate.length === 0) {
+		return true
+	}
+
 	return currentTemplate !== inheritedTemplate
 })
 
@@ -267,7 +271,10 @@ function onCustomizeFooterTemplateChange(customizeFooterTemplate: boolean) {
 		return
 	}
 
-	updateValue({ customizeFooterTemplate })
+	// When enabling customization, seed the template with the inherited default so the
+	// saved value is concrete and not dependent on future inherited-template resolution.
+	const seedTemplate = value.value.footerTemplate || (props.inheritedTemplate ?? '')
+	updateValue({ customizeFooterTemplate, footerTemplate: seedTemplate })
 }
 
 function onFooterTemplateChange(footerTemplate: string | number) {
@@ -283,9 +290,12 @@ function onTemplateReset(event?: Event) {
 	event?.stopPropagation()
 	event?.preventDefault()
 
+	// Reset to the concrete inherited template so the saved value is explicit and
+	// independent of future inherited-template resolution. Using '' (empty) as a
+	// sentinel would break when the inheritedTemplate changes between page loads.
 	updateValue({
 		customizeFooterTemplate: true,
-		footerTemplate: '',
+		footerTemplate: props.inheritedTemplate ?? '',
 	})
 	onTemplateChanged()
 }