Remove build-output.txt from repository

- Delete build-output.txt (build logs shouldn't be tracked)
- Add build-output.txt to .gitignore

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ANcpLua

.gitignore

@@ -153,6 +153,7 @@ ocr/
 # Test outputs
 CreatePdf.NET.Tests/output/
 test_output.txt
+build-output.txt
 
 # Coverage results
 coverage-results/