Add Asistente chat page with A2UI render tools

Wires CopilotKit v2 chat into the SPA as the Asistente page,
declares a render_spending_summary action backed by a custom
SpendingSummaryCard, and configures static suggestions shown
before the first message.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/pages/Asistente.tsx

@@ -0,0 +1,80 @@
+import { CopilotChat, useConfigureSuggestions } from "@copilotkit/react-core/v2";
+import { useCopilotAction } from "@copilotkit/react-core";
+import { Sparkles } from "lucide-react";
+import { SpendingSummaryCard, type SpendingSummaryArgs } from "@/components/chat/ChatCards";
+
+const STATIC_SUGGESTIONS = {
+  available: "before-first-message" as const,
+  suggestions: [
+    { title: "¿Cuál es mi saldo neto hoy?", message: "¿Cuál es mi saldo neto hoy?" },
+    { title: "¿Cuánto gasté en el ciclo anterior?", message: "¿Cuánto gasté en el ciclo anterior?" },
+    { title: "Últimas 10 transacciones", message: "Muéstrame mis últimas 10 transacciones" },
+    { title: "¿Cómo va mi pensión?", message: "¿Cómo va mi pensión?" },
+  ],
+};
+
+export default function Asistente() {
+  useConfigureSuggestions(STATIC_SUGGESTIONS);
+
+  useCopilotAction({
+    name: "render_spending_summary",
+    description:
+      "Render a visual spending summary card with source breakdown and category progress bars. " +
+      "Call this for any cycle summary, spending totals, or category breakdown.",
+    parameters: [
+      { name: "title", type: "string", description: "Card title (e.g. 'Ciclo actual')" },
+      { name: "period", type: "string", description: "Human-readable period (e.g. '18 mar → 18 abr 2026')" },
+      { name: "total_crc", type: "number", description: "Total spend in CRC" },
+      {
+        name: "by_source",
+        type: "object[]",
+        description: "Breakdown by payment source",
+        attributes: [
+          { name: "source", type: "string" },
+          { name: "total_crc", type: "number" },
+          { name: "count", type: "number" },
+        ],
+      },
+      {
+        name: "by_category",
+        type: "object[]",
+        required: false,
+        description: "Top spending categories with CRC amounts",
+        attributes: [
+          { name: "category", type: "string" },
+          { name: "amount_crc", type: "number" },
+          { name: "count", type: "number" },
+        ],
+      },
+    ],
+    handler: async () => "ok",
+    render: (props) => (
+      <SpendingSummaryCard args={props.args as SpendingSummaryArgs} status={props.status} />
+    ),
+  });
+
+  return (
+    <div className="flex flex-col h-[calc(100vh-105px)]">
+      <div className="mb-4">
+        <h1 className="text-2xl font-bold tracking-tight flex items-center gap-2" style={{ fontFamily: "var(--font-heading)" }}>
+          <Sparkles className="w-5 h-5 text-primary" />
+          Asistente
+        </h1>
+        <p className="text-sm text-muted-foreground">
+          Pregúntale a WealthySmart sobre tus finanzas.
+        </p>
+      </div>
+
+      <div className="flex-1 min-h-0 rounded-xl border border-border overflow-hidden bg-card">
+        <CopilotChat
+          className="h-full"
+          labels={{
+            modalHeaderTitle: "WealthySmart",
+            welcomeMessageText: "¿Qué quieres saber sobre tus finanzas?",
+            chatInputPlaceholder: "Escribe tu pregunta…",
+          }}
+        />
+      </div>
+    </div>
+  );
+}