feat: Add testimonials and update Gemini model

Integrates a testimonial system to display user results and feedback. This includes:
- Adding a new `testimonials` collection in Firestore.
- Implementing frontend components for displaying and submitting testimonials.
- Modifying the Gemini service to use the `gemini-3.1-pro-preview` model for enhanced analysis.
- Updating the `PlansView` with a new WhatsApp contact number.
- Enhancing the `AdminDashboard` to include testimonial creation capabilities.

src/components/ImageUploader.tsx

@@ -0,0 +1,48 @@
+import React, { useState } from 'react';
+import { ref, uploadBytes, getDownloadURL } from 'firebase/storage';
+import { storage, auth } from '../lib/firebase';
+
+interface ImageUploaderProps {
+  onUpload: (urls: string[]) => void;
+  className?: string;
+}
+
+export const ImageUploader: React.FC<ImageUploaderProps> = ({ onUpload, className }) => {
+  const [uploading, setUploading] = useState(false);
+
+  const handleFileChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
+    if (!e.target.files || e.target.files.length === 0 || !auth.currentUser) return;
+
+    const files = Array.from(e.target.files) as File[];
+    setUploading(true);
+
+    try {
+      const uploadPromises = files.map(async (file) => {
+        const storageRef = ref(storage, `testimonials/${auth.currentUser!.uid}/${Date.now()}_${file.name}`);
+        await uploadBytes(storageRef, file);
+        return getDownloadURL(storageRef);
+      });
+      const urls = await Promise.all(uploadPromises);
+      onUpload(urls);
+    } catch (error) {
+      console.error(error);
+      alert('Erro ao fazer upload das imagens.');
+    } finally {
+      setUploading(false);
+    }
+  };
+
+  return (
+    <div className={className}>
+      <input
+        type="file"
+        accept="image/*"
+        multiple
+        onChange={handleFileChange}
+        disabled={uploading}
+        className="w-full bg-white/5 border border-white/10 rounded-lg p-3 text-white focus:outline-none focus:ring-1 focus:ring-brand-red text-sm"
+      />
+      {uploading && <p className="text-xs text-brand-red mt-1">Enviando imagens...</p>}
+    </div>
+  );
+};