Widen payment amount validation to 10,000-20,000,000 VNĐ (inclusive)

Replaces the strict >1,000,000/<20,000,000 range with an inclusive
>=10,000/<=20,000,000 range, matching the actual usable range confirmed
on the real Sổ Bán Lẻ catalog after the earlier per-line-qty fix.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017KPzWwuTEeX2vXGXvyGn4q

app/controllers/admin.server.controller.js

@@ -29,8 +29,8 @@ exports.createTransaction = function (req, res) {
   if (
     !isFinite(targetAmount) ||
     String(targetAmount) !== String(rawAmount).trim() ||
-    targetAmount <= 1000000 ||
-    targetAmount >= 20000000
+    targetAmount < 10000 ||
+    targetAmount > 20000000
   ) {
     return res.status(400).json({ code: "99", data: "INVALID_AMOUNT" });
   }

app/views/admin/transactions-new.server.view.html

@@ -407,12 +407,12 @@
         <div class="field" data-field="amount">
           <label for="amount">Số tiền thanh toán</label>
           <div class="amount-field">
-            <input type="number" id="amount" name="amount" placeholder="0" min="1000001" max="19999999" step="1" inputmode="numeric" required aria-describedby="amount-error amount-preview">
+            <input type="number" id="amount" name="amount" placeholder="0" min="10000" max="20000000" step="1" inputmode="numeric" required aria-describedby="amount-error amount-preview">
             <span class="amount-suffix">VNĐ</span>
           </div>
           <p class="field-error" id="amount-error" role="alert">
             <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"/><line x1="12" y1="8" x2="12" y2="12"/><line x1="12" y1="16" x2="12.01" y2="16"/></svg>
-            Số tiền phải lớn hơn 1,000,000 và nhỏ hơn 20,000,000 VNĐ
+            Số tiền phải từ 10,000 đến 20,000,000 VNĐ
           </p>
           <p class="amount-preview" id="amount-preview" aria-live="polite"></p>
           <div class="amount-presets" role="group" aria-label="Chọn nhanh số tiền">
@@ -484,7 +484,7 @@
       if (!data.customerAddress.trim()) { setFieldInvalid('customerAddress'); valid = false; } else { setFieldValid('customerAddress'); }
       if (!data.customerIdCard.trim()) { setFieldInvalid('customerIdCard'); valid = false; } else { setFieldValid('customerIdCard'); }
       var amountNum = parseInt(data.amount, 10);
-      if (!isFinite(amountNum) || amountNum <= 1000000 || amountNum >= 20000000) { setFieldInvalid('amount'); valid = false; } else { setFieldValid('amount'); }
+      if (!isFinite(amountNum) || amountNum < 10000 || amountNum > 20000000) { setFieldInvalid('amount'); valid = false; } else { setFieldValid('amount'); }
       return valid;
     }