Add copilot instructions file

Author: DanVanAtta

.github/copilot-instructions.md

@@ -0,0 +1,21 @@
+Use `make verify` to validate the project
+
+## Tech Stack
+- Java 21, DropWizard (HTTP server), JDBI (no ORM), Postgres, Lombok
+- Gradle build with shadow JAR as deployment artifact
+- Docker + docker-compose for local dev and integration tests
+
+## Testing
+- `src/test/` — unit tests; no database or server required
+- `src/testInteg/` — integration tests; require Docker (docker-compose spins up a live DB and server automatically via Gradle)
+- Do not put integration tests in `src/test/` or unit tests in `src/testInteg/`
+
+## Code Style
+- Google Java Format is enforced via Spotless (`make format` or `./gradlew spotlessApply`)
+- No wildcard imports (Spotless removes them)
+- Use Lombok annotations (`@Value`, `@Builder`, `@Data`, `@RequiredArgsConstructor`, etc.) instead of hand-written boilerplate
+
+## Database
+- No ORM — use JDBI with SQL object pattern
+- Database migrations go in `database/migrations/` as Flyway `.sql` files
+- Migration naming convention: `V{major}.{minor}.{patch}__description.sql`