Add user auth, personal cabinet, admin panel and first admin bootstrap

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

app/auth_utils.py

@@ -0,0 +1,28 @@
+from functools import wraps
+
+from flask import abort, flash, redirect, url_for
+from flask_login import current_user
+
+
+def admin_required(f):
+    @wraps(f)
+    def decorated(*args, **kwargs):
+        if not current_user.is_authenticated or not current_user.is_admin:
+            flash("Доступ только для администраторов", "error")
+            return redirect(url_for("main.index"))
+        return f(*args, **kwargs)
+
+    return decorated
+
+
+def can_manage_photo(photo):
+    if not current_user.is_authenticated:
+        return False
+    if current_user.is_admin:
+        return True
+    return photo.user_id == current_user.id
+
+
+def photo_owner_or_admin(photo):
+    if not can_manage_photo(photo):
+        abort(403)