#2: add trading account type type and fix schema migrations machinery

brmbar3/schema/0001-init.sql

@@ -1,5 +1,5 @@
 --
--- 0000-init.sql
+-- 0001-init.sql
 --
 -- Initial SQL schema construction as of 2025-04-20 (or so)
 --
@@ -273,7 +273,7 @@ BEGIN
 
     CREATE OR REPLACE FUNCTION brmbar_privileged.has_exact_schema_version(
 	    IN i_ver INTEGER
-    ) RETURNS INTEGER
+    ) RETURNS BOOLEAN
     VOLATILE  NOT LEAKPROOF  LANGUAGE plpgsql AS $x$
     DECLARE
 	    v_ver INTEGER;
@@ -292,7 +292,7 @@ BEGIN
 
     CREATE OR REPLACE FUNCTION brmbar_privileged.upgrade_schema_version_to(
 	    IN i_ver INTEGER
-    ) RETURNS INTEGER
+    ) RETURNS VOID
     VOLATILE  NOT LEAKPROOF  LANGUAGE plpgsql AS $x$
     DECLARE
 	    v_ver INTEGER;

brmbar3/schema/0002-trading-accounts.sql

@@ -0,0 +1,37 @@
+--
+-- 0002-trading-accounts.sql
+--
+-- #2 - add trading accounts to account type type
+--
+-- ISC License
+--
+-- Copyright 2023-2025 Brmlab, z.s.
+-- Dominik Pantůček <dominik.pantucek@trustica.cz>
+--
+-- Permission to use, copy, modify, and/or distribute this software
+-- for any purpose with or without fee is hereby granted, provided
+-- that the above copyright notice and this permission notice appear
+-- in all copies.
+-- 
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+-- WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+-- WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+-- AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+-- CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+-- OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+-- NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+DO $upgrade_block$
+BEGIN
+
+IF brmbar_privileged.has_exact_schema_version(1) THEN
+
+  ALTER TYPE public.account_type ADD VALUE 'trading';
+  
+  PERFORM brmbar_privileged.upgrade_schema_version_to(2);
+END IF;
+
+END;
+$upgrade_block$;