update: add new logic for push token

database/migrations/update_push_tokens_to_array.sql

@@ -0,0 +1,28 @@
+-- Update push notification token field to support multiple devices
+-- Step 1: Add new push_tokens JSON array column
+ALTER TABLE users ADD COLUMN push_tokens JSONB DEFAULT NULL;
+
+-- Step 2: Migrate existing single push_token data to the new array format
+UPDATE users
+SET
+    push_tokens = CASE
+        WHEN push_token IS NOT NULL
+        AND push_token != '' THEN jsonb_build_array (push_token)
+        ELSE NULL
+    END
+WHERE
+    push_token IS NOT NULL;
+
+-- Step 3: Drop the old single push_token column
+ALTER TABLE users DROP COLUMN IF EXISTS push_token;
+
+-- Step 4: Add index for better performance on push_tokens
+CREATE INDEX IF NOT EXISTS idx_users_push_tokens ON users USING GIN (push_tokens)
+WHERE
+    push_tokens IS NOT NULL
+    AND push_tokens != 'null'::jsonb
+    AND jsonb_array_length(push_tokens) > 0
+    AND deleted_at IS NULL;
+
+-- Step 5: Add comment for documentation
+COMMENT ON COLUMN users.push_tokens IS 'JSON array of Najva push notification tokens from different user devices';