chore: add backend gitignore and remove target class files from git

backend/.gitignore

@@ -0,0 +1,9 @@
+/target/
+/.settings/
+/.classpath
+/.project
+/.metadata/
+/bin/
+*.class
+.factorypath
+.springBeans

backend/target/classes/application.properties

@@ -1,13 +0,0 @@
-# ─── DATABASE CONNECTION CONFIGURATION ───
-spring.datasource.url=jdbc:postgresql://localhost:5432/rit_freshers_hub?sslmode=disable
-spring.datasource.username=postgres
-spring.datasource.password=Amudiesh22@.
-
-# ─── JPA / HIBERNATE SETTINGS ───
-spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
-spring.jpa.hibernate.ddl-auto=validate
-spring.jpa.show-sql=true
-spring.jpa.properties.hibernate.format_sql=true
-
-# ─── SERVER PORT ───
-server.port=8080