fix(a11y): label associations for AdminPromoOfferTemplateEdit fields

Add htmlFor/id pairs for template name, message text, button text, valid hours,
discount percent, test duration, and active discount hours (WCAG 1.3.1). Test-squads
section is a checkbox group, not a single control.

src/pages/AdminPromoOfferTemplateEdit.tsx

@@ -138,11 +138,15 @@ export default function AdminPromoOfferTemplateEdit() {
         <div className="rounded-xl border border-dark-700 bg-dark-800 p-6">
           <div className="space-y-4">
             <div>
-              <label className="mb-2 block text-sm font-medium text-dark-300">
+              <label
+                htmlFor="po-template-name"
+                className="mb-2 block text-sm font-medium text-dark-300"
+              >
                 {t('admin.promoOffers.form.templateName')}
                 <span className="text-error-400">*</span>
               </label>
               <input
+                id="po-template-name"
                 type="text"
                 value={name}
                 onChange={(e) => setName(e.target.value)}
@@ -151,11 +155,15 @@ export default function AdminPromoOfferTemplateEdit() {
             </div>
 
             <div>
-              <label className="mb-2 block text-sm font-medium text-dark-300">
+              <label
+                htmlFor="po-message-text"
+                className="mb-2 block text-sm font-medium text-dark-300"
+              >
                 {t('admin.promoOffers.form.messageText')}
                 <span className="text-error-400">*</span>
               </label>
               <textarea
+                id="po-message-text"
                 value={messageText}
                 onChange={(e) => setMessageText(e.target.value)}
                 rows={4}
@@ -164,11 +172,15 @@ export default function AdminPromoOfferTemplateEdit() {
             </div>
 
             <div>
-              <label className="mb-2 block text-sm font-medium text-dark-300">
+              <label
+                htmlFor="po-button-text"
+                className="mb-2 block text-sm font-medium text-dark-300"
+              >
                 {t('admin.promoOffers.form.buttonText')}
                 <span className="text-error-400">*</span>
               </label>
               <input
+                id="po-button-text"
                 type="text"
                 value={buttonText}
                 onChange={(e) => setButtonText(e.target.value)}
@@ -178,10 +190,14 @@ export default function AdminPromoOfferTemplateEdit() {
 
             <div className="grid grid-cols-1 gap-4 sm:grid-cols-2">
               <div>
-                <label className="mb-2 block text-sm font-medium text-dark-300">
+                <label
+                  htmlFor="po-valid-hours"
+                  className="mb-2 block text-sm font-medium text-dark-300"
+                >
                   {t('admin.promoOffers.form.validHours')}
                 </label>
                 <input
+                  id="po-valid-hours"
                   type="number"
                   value={validHours}
                   onChange={createNumberInputHandler(setValidHours, 1)}
@@ -196,10 +212,14 @@ export default function AdminPromoOfferTemplateEdit() {
 
               {!isTestAccess && (
                 <div>
-                  <label className="mb-2 block text-sm font-medium text-dark-300">
+                  <label
+                    htmlFor="po-discount-percent"
+                    className="mb-2 block text-sm font-medium text-dark-300"
+                  >
                     {t('admin.promoOffers.form.discountPercent')}
                   </label>
                   <input
+                    id="po-discount-percent"
                     type="number"
                     value={discountPercent}
                     onChange={createNumberInputHandler(setDiscountPercent, 0, 100)}
@@ -215,10 +235,14 @@ export default function AdminPromoOfferTemplateEdit() {
             {isTestAccess ? (
               <>
                 <div>
-                  <label className="mb-2 block text-sm font-medium text-dark-300">
+                  <label
+                    htmlFor="po-test-duration-hours"
+                    className="mb-2 block text-sm font-medium text-dark-300"
+                  >
                     {t('admin.promoOffers.form.testDurationHours')}
                   </label>
                   <input
+                    id="po-test-duration-hours"
                     type="number"
                     value={testDurationHours}
                     onChange={createNumberInputHandler(setTestDurationHours, 0)}
@@ -283,10 +307,14 @@ export default function AdminPromoOfferTemplateEdit() {
               </>
             ) : (
               <div>
-                <label className="mb-2 block text-sm font-medium text-dark-300">
+                <label
+                  htmlFor="po-active-discount-hours"
+                  className="mb-2 block text-sm font-medium text-dark-300"
+                >
                   {t('admin.promoOffers.form.activeDiscountHours')}
                 </label>
                 <input
+                  id="po-active-discount-hours"
                   type="number"
                   value={activeDiscountHours}
                   onChange={createNumberInputHandler(setActiveDiscountHours, 0)}