diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..2bb33e7
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,15 @@
+# Line endings are not cosmetic for these.
+#
+# The Maven wrapper is a shell script executed on Linux runners: committed with CRLF, its shebang
+# reads as an interpreter named "/bin/sh\r", which does not exist, and the build dies with exit 127
+# before Maven ever starts. Checking these out as LF everywhere is what keeps that from recurring.
+mvnw            text eol=lf
+*.sh            text eol=lf
+Dockerfile      text eol=lf
+*.yml           text eol=lf
+*.yaml          text eol=lf
+
+# Windows counterparts, which need the opposite.
+mvnw.cmd        text eol=crlf
+*.bat           text eol=crlf
+*.ps1           text eol=crlf
diff --git a/Analytics-Service/mvnw b/Analytics-Service/mvnw
old mode 100644
new mode 100755
diff --git a/Library-Management-System-Version-2/pom.xml b/Library-Management-System-Version-2/pom.xml
index d321804..a6283d3 100644
--- a/Library-Management-System-Version-2/pom.xml
+++ b/Library-Management-System-Version-2/pom.xml
@@ -260,8 +260,12 @@
 				<artifactId>maven-compiler-plugin</artifactId>
 				<version>3.11.0</version>
 				<configuration>
-					<source>${java.version}</source>
-					<target>${java.version}</target>
+					<!--
+						release, not source/target: those emit 21 bytecode but still compile against
+						whatever JDK is installed, so an API added after 21 builds on a developer's
+						machine and fails on a JDK 21 runner. release pins the API surface too.
+					-->
+					<release>${java.version}</release>
 					<annotationProcessorPaths>
 						<path>
 							<groupId>org.projectlombok</groupId>
diff --git a/Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportAuthorDto.java b/Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportAuthorDto.java
similarity index 100%
rename from Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportAuthorDto.java
rename to Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportAuthorDto.java
diff --git a/Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportBookDto.java b/Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportBookDto.java
similarity index 100%
rename from Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportBookDto.java
rename to Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportBookDto.java
diff --git a/Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportCustomerDto.java b/Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportCustomerDto.java
similarity index 100%
rename from Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportCustomerDto.java
rename to Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportCustomerDto.java
diff --git a/Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportTransactionDto.java b/Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportTransactionDto.java
similarity index 100%
rename from Library-Management-System-Version-2/src/main/java/app/domain/dto/importData/ImportTransactionDto.java
rename to Library-Management-System-Version-2/src/main/java/app/domain/dto/importdata/ImportTransactionDto.java