feat: implement offline queue, background sync and AI robustness

supa_schema.sql

@@ -40,6 +40,8 @@ CREATE TABLE IF NOT EXISTS bottles (
   status TEXT DEFAULT 'sealed' CHECK (status IN ('sealed', 'open', 'empty')),
   whiskybase_id TEXT,
   image_url TEXT,
+  is_whisky BOOLEAN DEFAULT true,
+  confidence INTEGER DEFAULT 100,
   created_at TIMESTAMP WITH TIME ZONE DEFAULT timezone('utc'::text, now()),
   updated_at TIMESTAMP WITH TIME ZONE DEFAULT timezone('utc'::text, now())
 );