DataProcessor 'wirteFile' has typo and resource leak

[aliAljaffer]

As a developer
I want proper file writing with correct spelling
So that the API is professional and doesn't leak resources

Current Behavior

1. Method name: wirteFile() instead of writeFile()
2. FileWriter never closed - resource leak

Location: src/java/DataProcessor.java line 23

Acceptance Criteria

• Rename to writeFile()
• Use try-with-resources for FileWriter
• Test proper file closing