feat: Add initial frontend dependencies, base CSS, and Gitea Docker build workflow.

backend/src/main/resources/application.properties

@@ -0,0 +1,7 @@
+spring.application.name=backend
+spring.datasource.url=jdbc:postgresql://localhost:5432/tododb
+spring.datasource.username=postgres
+spring.datasource.password=postgres
+spring.jpa.hibernate.ddl-auto=update
+spring.jpa.show-sql=true
+spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect