feat: release v1.8.0 — connections dashboard, VK OAuth, sync config, catalog browser

- Connections dashboard with add/remove flow and background health checks
- VK OAuth connection with profile info and health monitoring
- Sync configuration page with master toggle and filter summary
- Catalog browser with store/group/product tables, filter management, CSV export
- Alembic migrations for all new tables
- run/read_config.py for shell sync script DB integration
- CHANGELOG.md updated for v1.8.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/templates/connections_add.html

@@ -0,0 +1,39 @@
+{% extends "base.html" %}
+{% block title %}Добавить подключение — EvoSync{% endblock %}
+
+{% block content %}
+<div class="d-flex align-items-center mb-4">
+    <a href="/connections" class="text-muted me-3"><i class="bi bi-arrow-left fs-5"></i></a>
+    <h1 class="h4 mb-0">Добавить подключение</h1>
+</div>
+
+{% if available %}
+<div class="row g-3">
+    {% for svc in available %}
+    <div class="col-sm-6 col-lg-4">
+        <div class="card shadow-sm h-100">
+            <div class="card-body d-flex flex-column">
+                <div class="d-flex align-items-center mb-3">
+                    <i class="bi {{ svc.icon }} fs-2 me-3 text-secondary"></i>
+                    <h5 class="mb-0">{{ svc.name }}</h5>
+                </div>
+                <p class="text-muted small flex-grow-1">{{ svc.description }}</p>
+                <a href="{{ svc.connect_url }}" class="btn btn-primary btn-sm mt-auto">
+                    Подключить <i class="bi bi-arrow-right ms-1"></i>
+                </a>
+            </div>
+        </div>
+    </div>
+    {% endfor %}
+</div>
+
+{% else %}
+<div class="text-center py-5 text-muted">
+    <i class="bi bi-check-circle fs-1 mb-3 d-block text-success"></i>
+    <p class="mb-3">Все доступные сервисы подключены</p>
+    <a href="/connections" class="btn btn-outline-secondary btn-sm">
+        <i class="bi bi-arrow-left me-1"></i>Вернуться к подключениям
+    </a>
+</div>
+{% endif %}
+{% endblock %}