feat(zones): profile-scoped groups, zone modes, sequence brightness

- Optional profile_id on groups; UI and API for shared vs profile-only groups\n- Zone content_kind (presets vs sequences); edit modal shows matching sections; devices via groups only\n- Server sequence playback folds zone brightness into preset wire b (per MAC where needed)\n- Related preset/sequence/audio/beat-route and client updates

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

src/models/zone.py

@@ -19,7 +19,11 @@ def _maybe_migrate_tab_json_to_zone():
 
 
 class Zone(Model):
-    """Preset layout row (stored in ``db/zone.json``); legacy storage was ``tab.json`` / Tab."""
+    """Preset layout row (stored in ``db/zone.json``); legacy storage was ``tab.json`` / Tab.
+
+    Optional ``content_kind`` on a row: ``\"presets\"`` (preset tiles only) or ``\"sequences\"``
+    (sequence tiles only). Omitted or unknown => both (legacy behaviour).
+    """
 
     def __init__(self):
         if not getattr(Zone, "_migration_checked", False):
@@ -42,12 +46,12 @@ class Zone(Model):
         if changed:
             self.save()
 
-    def create(self, name="", names=None, presets=None, group_ids=None):
+    def create(self, name="", names=None, presets=None, group_ids=None, content_kind=None):
         next_id = self.get_next_id()
         gid_list = []
         if isinstance(group_ids, list):
-            gid_list = [str(x) for x in group_ids if x is not None]
-        self[next_id] = {
+            gid_list = [str(x).strip() for x in group_ids if x is not None and str(x).strip()]
+        doc = {
             "name": name,
             "names": names if names else [],
             "group_ids": gid_list,
@@ -56,6 +60,9 @@ class Zone(Model):
             "default_preset": None,
             "brightness": 255,
         }
+        if content_kind in ("presets", "sequences"):
+            doc["content_kind"] = content_kind
+        self[next_id] = doc
         self.save()
         return next_id