feat: add NixOS support, Go, and Ruby on Rails; remove Rust

- Add nixos/ directory with declarative flake.nix and home.nix for NixOS
- Make all setup scripts NixOS-aware with proper detection and early exit
- Update bashrc, zshrc, and aliases with Go, Ruby on Rails, and Nix profile paths
- Replace Rust/Cargo references in shell configs with rbenv/Ruby on Rails
- Update README with NixOS quick start and full documentation

README.md

@@ -1,16 +1,39 @@
 # Fresh Install
 
 This is a collection of scripts and dotfiles I use when setting up a fresh Linux installation.
+Now compatible with **NixOS** (declarative via flakes + home-manager), as well as traditional
+distributions like Fedora, Ubuntu, Debian, and Pop!_OS.
 
 ## Quick Start
 
+### Traditional Distros (Fedora / Ubuntu / Debian / Pop!_OS)
+
 Run the main setup script to install software, configure development tools, and symlink dotfiles:
 
 ```bash
 ./main-setup.sh
 ```
 
-The script will automatically detect your Linux distribution (Fedora, Ubuntu, Debian, etc.) and use the appropriate package manager.
+The script will automatically detect your Linux distribution and use the appropriate package manager.
+
+### NixOS
+
+On NixOS, packages and configuration are managed **declaratively** using the flake in the `nixos/` directory.
+Run the main script for a guided workflow:
+
+```bash
+./main-setup.sh
+```
+
+Or apply the flake directly:
+
+```bash
+# Rebuild system configuration
+sudo nixos-rebuild switch --flake ~/dotfiles/nixos#nixos
+
+# Apply user-level configuration
+home-manager switch --flake ~/dotfiles/nixos#blake
+```
 
 ## What Gets Installed
 
@@ -27,8 +50,10 @@ The script will automatically detect your Linux distribution (Fedora, Ubuntu, De
 - **Neovim** (latest version from GitHub)
 - **Hack Nerd Font** for terminal
 - **Oh My Zsh** shell framework
-- **Starship** prompt
-- **Rust** toolchain via rustup
+- **Oh My Posh** prompt
+- **Go** (Golang) with `gopls` language server and `delve` debugger
+- **Ruby on Rails** — Ruby via rbenv, Bundler, Rails gem, Node.js
+- **Python** development tools (pip, virtualenv, pynvim)
 
 ### Fedora-Specific (.NET Development)
 On Fedora systems, additional packages are installed:
@@ -37,13 +62,16 @@ On Fedora systems, additional packages are installed:
 - **PostgreSQL** server and tools
 - **Docker** (moby-engine) with Docker Compose
 
-### Flatpak Applications
+### Flatpak Applications (Traditional Distros Only)
 - Bitwarden
+- Discord
 - Flatseal
-- Steam
+- Podman Desktop
 - ProtonUp-Qt
-- Rider
-- Veloren Airshipper
+- Signal
+- Steam
+- Teams for Linux
+- Thunderbird
 - Visual Studio Code
 - VLC Media Player
 
@@ -51,10 +79,11 @@ On Fedora systems, additional packages are installed:
 
 The setup is broken down into focused scripts:
 
-- `00-system-prep.sh` - System updates and Flathub setup
-- `01-package-install.sh` - Core packages and Flatpak apps
-- `02-dev-tools-setup.sh` - Development tools (Neovim, Go, Rust, Helm, kubectx, stern, dive, trivy, AWS CLI)
-- `03-fedora-dotnet-setup.sh` - Fedora-specific .NET environment
+- `00-system-prep.sh` - System updates and Flathub setup (NixOS-aware)
+- `01-package-install.sh` - Core packages and Flatpak apps (NixOS-aware)
+- `02-dev-tools-setup.sh` - Development tools: Neovim, Hack Nerd Font, Go, Ruby on Rails,
+  Oh My Posh, Helm, kubectx, stern, dive, trivy, AWS CLI (NixOS-aware)
+- `03-fedora-dotnet-setup.sh` - Fedora-specific .NET environment (skipped on NixOS)
 - `04-config-symlinks.sh` - Dotfile symlinking
 
 You can run individual scripts if you only need specific components.
@@ -112,10 +141,31 @@ After running the setup, remember to:
 
 ## Supported Distributions
 
+- **NixOS** — Declarative via `nixos/flake.nix` + `nixos/home.nix`
 - **Fedora** (with full .NET development environment)
 - **Ubuntu/Debian** (core packages and development tools)
 - **Pop!_OS** (core packages and development tools)
 
+## NixOS Setup (nixos/)
+
+The `nixos/` directory contains a declarative flake-based configuration:
+
+### Files
+
+- **`nixos/flake.nix`** — NixOS system configuration:
+  - System packages (Go, Ruby, Python, Kubernetes tools, networking tools)
+  - Docker, Flatpak, and virt-manager services
+  - Zsh as default shell
+  - Hack & FiraCode Nerd Fonts
+  - Neovim as default editor
+
+- **`nixos/home.nix`** — Home-manager user configuration:
+  - User packages (Go tooling, Ruby on Rails, shell tools, cloud tools)
+  - Zsh aliases and environment (Go, Ruby/Rails, Kubernetes, Docker, AWS, Terraform)
+  - Git configuration with template and includes
+  - Dotfile symlinks (bashrc, zshrc, aliases, gitconfig, gitignore)
+  - Oh My Posh theme and Nushell config
+
 ## Customization
 
 Feel free to fork this repository and modify the scripts/dotfiles to suit your needs. The modular structure makes it easy to add, remove, or modify specific components.