Adds pagination to transaction history

Implements pagination for the transaction history, enabling users
to navigate through their transactions in manageable chunks. This
improves performance and user experience, especially for users
with a large number of transactions. It also introduces total entry counts.

static/js/index.js

@@ -10,6 +10,13 @@ window.app = Vue.createApp({
       balance: null,
       allUserBalances: [],
       transactions: [],
+      transactionPagination: {
+        total: 0,
+        limit: 20,
+        offset: 0,
+        has_next: false,
+        has_prev: false
+      },
       accounts: [],
       currencies: [],
       users: [],
@@ -306,18 +313,39 @@ window.app = Vue.createApp({
         console.error('Error loading all user balances:', error)
       }
     },
-    async loadTransactions() {
+    async loadTransactions(offset = null) {
       try {
+        // Use provided offset or current pagination offset
+        const currentOffset = offset !== null ? offset : this.transactionPagination.offset
+
         const response = await LNbits.api.request(
           'GET',
-          '/castle/api/v1/entries/user',
+          `/castle/api/v1/entries/user?limit=${this.transactionPagination.limit}&offset=${currentOffset}`,
           this.g.user.wallets[0].inkey
         )
-        this.transactions = response.data
+
+        // Update transactions and pagination info
+        this.transactions = response.data.entries
+        this.transactionPagination.total = response.data.total
+        this.transactionPagination.offset = response.data.offset
+        this.transactionPagination.has_next = response.data.has_next
+        this.transactionPagination.has_prev = response.data.has_prev
       } catch (error) {
         LNbits.utils.notifyApiError(error)
       }
     },
+    nextTransactionsPage() {
+      if (this.transactionPagination.has_next) {
+        const newOffset = this.transactionPagination.offset + this.transactionPagination.limit
+        this.loadTransactions(newOffset)
+      }
+    },
+    prevTransactionsPage() {
+      if (this.transactionPagination.has_prev) {
+        const newOffset = Math.max(0, this.transactionPagination.offset - this.transactionPagination.limit)
+        this.loadTransactions(newOffset)
+      }
+    },
     async loadAccounts() {
       try {
         const response = await LNbits.api.request(