test(query): verify persisted AVG1 state compatibility

Signed-off-by: discord9 <discord9@163.com>

tests/compatibility/cases/avg_state_binary/setup.sql

@@ -0,0 +1,14 @@
+CREATE TABLE avg1_states (
+  seq_id INT PRIMARY KEY,
+  state BINARY,
+  ts TIMESTAMP TIME INDEX
+);
+
+-- AVG1: magic (4 bytes), little-endian u64 count, little-endian f64 sum.
+INSERT INTO avg1_states (seq_id, state, ts) VALUES
+  (1, X'4156473102000000000000000000000000000840', '2026-01-01 00:00:00'),
+  (2, X'4156473101000000000000000000000000001840', '2026-01-01 00:00:01'),
+  (3, NULL, '2026-01-01 00:00:02'),
+  (4, X'4156473100000000000000000000000000000000', '2026-01-01 00:00:03');
+
+ADMIN FLUSH_TABLE('avg1_states');