wip: api filters and migration helpers

scripts/lowercase-columns.sql

@@ -0,0 +1,32 @@
+DO $$
+DECLARE
+    r RECORD;
+BEGIN
+    FOR r IN
+        SELECT table_schema, table_name, column_name
+        FROM information_schema.columns
+        WHERE table_schema = 'public'
+          AND column_name <> lower(column_name)
+        ORDER BY table_name, column_name
+    LOOP
+        -- Skip if a lowercase version already exists to avoid collisions.
+        IF EXISTS (
+            SELECT 1
+            FROM information_schema.columns c
+            WHERE c.table_schema = r.table_schema
+              AND c.table_name = r.table_name
+              AND c.column_name = lower(r.column_name)
+        ) THEN
+            RAISE NOTICE 'Skip %.%: % -> % (target exists)', r.table_name, r.column_name, r.column_name, lower(r.column_name);
+        ELSE
+            EXECUTE format(
+                'ALTER TABLE %I.%I RENAME COLUMN %I TO %I',
+                r.table_schema,
+                r.table_name,
+                r.column_name,
+                lower(r.column_name)
+            );
+            RAISE NOTICE 'Renamed %.%: % -> %', r.table_name, r.column_name, r.column_name, lower(r.column_name);
+        END IF;
+    END LOOP;
+END $$;