Add folders with password sharing and email invites

Co-authored-by: Cursor <cursoragent@cursor.com>

app/templates/share/folder.html

@@ -0,0 +1,47 @@
+{% extends "base.html" %}
+
+{% block title %}{{ folder.name }} — Shared folder{% endblock %}
+
+{% block content %}
+<section class="page-header">
+    <div class="container">
+        <h1 class="page-header__title">📁 {{ folder.name }}</h1>
+        <p class="page-header__subtitle">Общая папка · {{ photos|length }} фото</p>
+        {% if share_url %}
+        <div class="page-header__actions">
+            <button type="button" class="btn btn--ghost copy-btn" data-url="{{ share_url }}">Копировать ссылку</button>
+        </div>
+        {% endif %}
+    </div>
+</section>
+
+{% include "partials/alerts.html" %}
+
+{% if can_edit %}
+<section id="upload" class="upload-section">
+    <div class="container">
+        <h2 class="section-title">Загрузить в папку</h2>
+        <form action="{{ url_for('main.upload') }}" method="post" enctype="multipart/form-data" class="upload-form" id="uploadForm">
+            <input type="hidden" name="folder_id" value="{{ folder.id }}">
+            <div class="dropzone" id="dropzone">
+                <input type="file" name="photo" id="photoInput" accept="image/png,image/jpeg,image/gif,image/webp,image/bmp" hidden>
+                <p class="dropzone__title">Перетащите фото сюда</p>
+                <div class="dropzone__preview" id="preview" hidden>
+                    <img id="previewImg" alt="Предпросмотр">
+                    <span id="previewName"></span>
+                </div>
+            </div>
+            <button type="submit" class="btn btn--primary" id="submitBtn" disabled>Загрузить</button>
+        </form>
+    </div>
+</section>
+{% endif %}
+
+<section class="gallery-section">
+    <div class="container">
+        {% with photos=photos, empty_title='В папке пока нет фото' %}
+        {% include "partials/photo_gallery.html" %}
+        {% endwith %}
+    </div>
+</section>
+{% endblock %}