Clean repository following Unix philosophy

- Remove deprecated installer scripts (install.sh, boot.sh, install-simple.sh)
- Remove large QCOW2 image files (12MB + 8MB)
- Remove outdated documentation files
- Remove deprecated omnixy scripts from scripts/ directory
- Update README.md with current implementation:
  - Document flake-based installation (recommended approach)
  - Add ISO building instructions
  - Update theme list (11 themes available)
  - Document pure Wayland architecture
  - Update project structure documentation
  - Remove references to deleted scripts
- Update .gitignore for GitHub:
  - Add Nix build outputs and ISO files
  - Add system and editor-specific files
  - Add large media files and archives
  - Add development environment files

This cleanup reduces repository size and focuses on the declarative
Nix flake approach, removing imperative installation scripts in favor
of standard NixOS tooling.

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

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

.gitignore

@@ -1 +1,129 @@
+# Reference directories
 ./omarchy_ref/*
+./omarchy/
+
+# Nix build outputs
+result
+result-*
+*.drv
+
+# ISO and disk images
+*.iso
+*.qcow2
+*.img
+*.vdi
+*.vmdk
+
+# Build artifacts
+*.o
+*.so
+*.a
+*.out
+build/
+dist/
+target/
+
+# Temporary files
+*.tmp
+*.temp
+*.swp
+*.swo
+*~
+.#*
+\#*#
+
+# System files
+.DS_Store
+Thumbs.db
+desktop.ini
+
+# Editor and IDE files
+.vscode/
+.idea/
+*.iml
+.project
+.classpath
+.settings/
+*.sublime-*
+
+# Vim
+*.vim
+.vim/
+Session.vim
+.netrwhist
+
+# Emacs
+*~
+\#*\#
+/.emacs.desktop
+/.emacs.desktop.lock
+*.elc
+auto-save-list
+tramp
+.\#*
+
+# Backup files
+*.bak
+*.backup
+*.old
+
+# Log files
+*.log
+logs/
+*.log.*
+
+# Cache directories
+.cache/
+cache/
+__pycache__/
+*.pyc
+
+# Environment files
+.env
+.env.local
+.env.*.local
+
+# SSH keys and secrets
+*.key
+*.pem
+id_rsa
+id_rsa.pub
+secrets/
+
+# Large media files
+*.mp4
+*.avi
+*.mov
+*.mkv
+*.zip
+*.tar.gz
+*.tar.xz
+*.7z
+*.rar
+
+# Node modules (if any JavaScript projects)
+node_modules/
+
+# Python virtual environments
+venv/
+.venv/
+env/
+.env/
+
+# Rust
+Cargo.lock
+
+# Go
+vendor/
+go.sum
+
+# Claude Code
+.claude/
+
+# Hardware configuration (system-specific)
+# Uncomment if you don't want to track hardware-configuration.nix
+# hardware-configuration.nix
+
+# Nix direnv
+.direnv/
+.envrc