chore add core rust project files and diesel migrations

Track required workspace crates, scripts, and historical diesel migrations so the repository contains the complete runnable backend baseline.

Made-with: Cursor

htykc_models/src/lib.rs

@@ -0,0 +1,9 @@
+#[macro_use]
+extern crate diesel;
+#[macro_use]
+extern crate serde_derive;
+// extern crate time;
+
+pub mod models;
+
+mod schema;