Enhance build system and logging configuration

- Add scripts/build.sh to compile binaries into bin/ directory

- Move all zerolog setup logic from cmd/server/main.go to pkg/config

- Add log level configuration support (trace, debug, info, warn, error, fatal, panic)

- Simplify cmd/server/main.go from 57 to 27 lines (53% reduction)

- Update .gitignore to use bin/ directory instead of individual files

- Document build process and bin directory in AGENTS.md

- Maintain backward compatibility with all existing functionality

.gitignore

@@ -2,8 +2,7 @@
 *.exe
 *.test
 *.out
-server
-greet
+bin/
 
 # Dependency directories
 vendor/