feat(videochat): implement LiveKit integration for video chat functionality

- Add LiveKit client setup and token generation for room access.
- Implement room management functions including CreateRoom, OpenRoom, ListRooms, and DeleteRoom.
- Introduce participant management with ListParticipants and RemoveParticipant functions.
- Create tests for room and participant management, ensuring proper authentication and authorization.
- Add error handling for LiveKit API interactions.
- Define data structures for room metadata and token responses.
- Implement status endpoint for service availability check.

extrahome/migrations/1_create_siteconfig.up.sql

@@ -0,0 +1,7 @@
+CREATE TABLE siteconfig (
+    id BIGSERIAL PRIMARY KEY,
+    extrsite JSONB NOT NULL,
+    start_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    description TEXT NOT NULL DEFAULT '',
+    CONSTRAINT siteconfig_extrsite_object CHECK (jsonb_typeof(extrsite) = 'object')
+);