Changes castle wallet to a select field.

Updates the castle wallet ID input to a select field populated with available wallet options.
This change improves usability by providing a predefined list of wallet options.
It also disables the save button if no wallet is selected.

templates/castle/index.html

@@ -304,17 +304,19 @@
         </div>
       </q-banner>
 
-      <q-input
+      <q-select
         filled
         dense
-        v-model.trim="settingsDialog.castleWalletId"
-        label="Castle Wallet ID *"
-        placeholder="The wallet ID that represents the Castle"
+        emit-value
+        v-model="settingsDialog.castleWalletId"
+        :options="g.user.walletOptions"
+        label="Castle Wallet *"
         :readonly="!isSuperUser"
-      ></q-input>
+        :disable="!isSuperUser"
+      ></q-select>
 
       <div class="text-caption text-grey">
-        This wallet will be used for Castle operations and transactions.
+        Select the wallet that will be used for Castle operations and transactions.
       </div>
 
       <div class="row q-mt-lg">
@@ -324,6 +326,7 @@
           color="primary"
           type="submit"
           :loading="settingsDialog.loading"
+          :disable="!settingsDialog.castleWalletId"
         >
           Save Settings
         </q-btn>