Adds user settings for the Castle extension

Adds functionality to configure the Castle extension, including a wallet ID.

This allows administrators to customize the extension's behavior by specifying a dedicated wallet for castle operations.

static/js/index.js

@@ -11,6 +11,8 @@ window.app = Vue.createApp({
       transactions: [],
       accounts: [],
       currencies: [],
+      settings: null,
+      isAdmin: false,
       expenseDialog: {
         show: false,
         description: '',
@@ -25,6 +27,11 @@ window.app = Vue.createApp({
         show: false,
         amount: null,
         loading: false
+      },
+      settingsDialog: {
+        show: false,
+        castleWalletId: '',
+        loading: false
       }
     }
   },
@@ -95,6 +102,47 @@ window.app = Vue.createApp({
         LNbits.utils.notifyApiError(error)
       }
     },
+    async loadSettings() {
+      try {
+        const response = await LNbits.api.request(
+          'GET',
+          '/castle/api/v1/settings',
+          this.g.user.wallets[0].adminkey
+        )
+        this.settings = response.data
+        this.isAdmin = true
+      } catch (error) {
+        // Not admin or settings not available
+        this.isAdmin = false
+      }
+    },
+    showSettingsDialog() {
+      this.settingsDialog.castleWalletId = this.settings?.castle_wallet_id || ''
+      this.settingsDialog.show = true
+    },
+    async submitSettings() {
+      this.settingsDialog.loading = true
+      try {
+        await LNbits.api.request(
+          'PUT',
+          '/castle/api/v1/settings',
+          this.g.user.wallets[0].adminkey,
+          {
+            castle_wallet_id: this.settingsDialog.castleWalletId
+          }
+        )
+        this.$q.notify({
+          type: 'positive',
+          message: 'Settings updated successfully'
+        })
+        this.settingsDialog.show = false
+        await this.loadSettings()
+      } catch (error) {
+        LNbits.utils.notifyApiError(error)
+      } finally {
+        this.settingsDialog.loading = false
+      }
+    },
     async submitExpense() {
       this.expenseDialog.loading = true
       try {
@@ -188,5 +236,6 @@ window.app = Vue.createApp({
     await this.loadTransactions()
     await this.loadAccounts()
     await this.loadCurrencies()
+    await this.loadSettings()
   }
 })