feat: Add comprehensive test suite and cleanup step

- Split validation into 4 granular CI steps (Config, Timescale, Vector, Hybrid)
- Added cleanup step for Docker images in CI
- Created SQL test scripts in tests/ for robustness

tests/test-4-hybrid.sql

@@ -0,0 +1,40 @@
+-- Test 4: Hybrid (Timescale + Vector)
+\set ON_ERROR_STOP on
+
+DROP TABLE IF EXISTS hybrid_logs;
+
+CREATE TABLE hybrid_logs (
+    time TIMESTAMPTZ NOT NULL,
+    msg TEXT,
+    vec vector(2)
+);
+
+SELECT create_hypertable('hybrid_logs', 'time');
+
+INSERT INTO hybrid_logs (time, msg, vec) VALUES
+    (NOW(), 'log1', '[0,0]'),
+    (NOW() - INTERVAL '1 day', 'old_log', '[1,1]');
+
+-- Index
+CREATE INDEX ON hybrid_logs USING vchordrq (vec vector_l2_ops);
+
+-- Hybrid Query
+DO $$
+DECLARE
+    res_count int;
+BEGIN
+    -- Recent logs similar to [0.1, 0.1]
+    SELECT count(*) INTO res_count 
+    FROM (
+        SELECT * FROM hybrid_logs 
+        WHERE time > NOW() - INTERVAL '1 hour'
+        ORDER BY vec <-> '[0.1, 0.1]'
+        LIMIT 1
+    ) sub;
+
+    IF res_count != 1 THEN
+        RAISE EXCEPTION 'Hybrid query failed';
+    END IF;
+    RAISE NOTICE 'Hybrid Check: OK';
+END
+$$;