fix(build): use OUT_DIR for migration files (#1088)

- write generated migration files to OUT_DIR instead of source directory
- copy migration SQL files to OUT_DIR for inclusion in build artifacts
- use absolute paths from OUT_DIR in include_str! macros
- update consumer modules to include from OUT_DIR using concat! macro

these changes enable cdk to support nix sandbox builds

crates/cdk-sql-common/src/mint/auth/mod.rs

@@ -54,8 +54,9 @@ where
 }
 
 #[rustfmt::skip]
-mod migrations;
-
+mod migrations {
+    include!(concat!(env!("OUT_DIR"), "/migrations_mint_auth.rs"));
+}
 
 #[async_trait]
 impl<RM> MintAuthTransaction<database::Error> for SQLTransaction<RM>

crates/cdk-sql-common/src/mint/mod.rs

@@ -51,8 +51,9 @@ use crate::{
 mod auth;
 
 #[rustfmt::skip]
-mod migrations;
-
+mod migrations {
+    include!(concat!(env!("OUT_DIR"), "/migrations_mint.rs"));
+}
 
 #[cfg(feature = "auth")]
 pub use auth::SQLMintAuthDatabase;

crates/cdk-sql-common/src/wallet/mod.rs

@@ -28,7 +28,9 @@ use crate::{
 };
 
 #[rustfmt::skip]
-mod migrations;
+mod migrations {
+    include!(concat!(env!("OUT_DIR"), "/migrations_wallet.rs"));
+}
 
 /// Wallet SQLite Database
 #[derive(Debug, Clone)]