Перевод проекта на единую SQLite БД, WAL и обновление README для Windows

config/db/migrate/20260303200000_enable_sqlite_wal.rb

@@ -0,0 +1,11 @@
+Sequel.migration do
+  up do
+    run "PRAGMA journal_mode = WAL;"
+    run "PRAGMA synchronous = NORMAL;"
+  end
+
+  down do
+    run "PRAGMA journal_mode = DELETE;"
+    run "PRAGMA synchronous = FULL;"
+  end
+end