Refactor Nix configuration for improved cross-platform support

Major architectural improvements:
- Remove Vagrant/Packer infrastructure in favor of direct Linux support
- Add centralized version management (common/versions.nix)
- Create shared Home Manager base configuration
- Enhance package management with better categorization and documentation
- Add platform-agnostic shell aliases and Nix utilities
- Optimize build performance with improved substituter settings
- Simplify deployment with auto-detection commands (nixswitch, hmswitch)
- Update documentation to reflect new hybrid architecture

This migration moves from VM-based development to direct Linux configuration,
making the setup more maintainable and performant across macOS/Linux environments.

Author: svnlto

CLAUDE.md

@@ -6,35 +6,30 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ### macOS (nix-darwin)
 ```bash
-# Apply system configuration (replace 'rick' with your hostname)
-darwin-rebuild switch --flake ~/.config/nix#rick
+# Apply system configuration (auto-detects hostname)
+nixswitch
+
+# Or manually specify hostname
+sudo darwin-rebuild switch --flake ~/.config/nix#$(scutil --get LocalHostName)
 
 # Update and apply configuration
-git pull && darwin-rebuild switch --flake ~/.config/nix#rick
+git pull && nixswitch
 ```
 
-### Development VM (Vagrant)
+### Linux (Home Manager)
 ```bash
-# Start VM
-vagrant up
-
-# SSH into VM
-vagrant ssh
+# Apply generic Linux configuration
+hmswitch
 
-# Apply configuration changes
-vagrant provision
+# Apply user-specific configuration (if exists)
+hm-user
 
-# Inside VM: Apply home-manager configuration
-nix run home-manager/master -- switch --flake ~/.config/nix#vagrant --impure
-```
-
-### Cloud (EC2)
-```bash
-# Build AMI with Packer
-cd packer && packer build -var "aws_profile=dev" aws-ec2.pkr.hcl
+# Manual commands
+home-manager switch --flake ~/.config/nix#linux
+home-manager switch --flake ~/.config/nix#$(whoami)  # user-specific
 
-# Apply EC2 home-manager configuration
-nix run home-manager/master -- switch --flake ~/.config/nix#ec2 --impure
+# Update and apply configuration
+git pull && hmswitch
 ```
 
 ## Architecture Overview
@@ -84,15 +79,20 @@ This is a **cross-platform Nix configuration** managing both macOS hosts and Lin
 - **Add everywhere**: Edit `common/packages.nix` (corePackages or devPackages lists)
 - **macOS system packages**: Edit `common/packages.nix` (darwinSystemPackages list)
 - **macOS GUI apps**: Edit `systems/aarch64-darwin/homebrew.nix`
-- **Linux-specific packages**: Edit `systems/aarch64-linux/vagrant.nix` or `ec2.nix`
+- **Linux-specific packages**: Edit `systems/aarch64-linux/home-linux.nix`
 
 ### Adding New Hosts
 Create new configuration in `flake.nix`:
 ```nix
-"hostname" = darwinSystem {
+# For macOS
+"hostname" = mkDarwinSystem {
   hostname = "hostname";
   username = "username";
-  # Additional config...
+};
+
+# For Linux
+"username" = mkHomeManagerConfig {
+  username = "username";
 };
 ```
 
@@ -109,9 +109,9 @@ Located in `common/claude-code/`, this provides:
 - **Node.js**: Uses nodePackages.pnpm from nixpkgs
 
 ### Multi-Environment Support
-- **Vagrant**: Local development VM with UTM integration
-- **EC2**: Cloud development with Packer AMI building
-- **Tailscale**: Secure connectivity for cloud instances
+- **Generic Linux**: Flexible Home Manager configuration for any Linux environment
+- **Development Shell**: Available via `nix develop` for working on this configuration
+- **Auto-Detection**: Shell aliases automatically detect system type and hostname
 
 ## Platform-Specific Notes
 

Vagrantfile

@@ -9,13 +9,25 @@
       experimental-features = [ "nix-command" "flakes" ];
       trusted-users = [ "root" username ];
 
-      # Settings to improve lock handling
+      # Performance optimizations
+      max-jobs = "auto";
+      cores = 0; # Use all available cores
+      build-cores = 0;
+
+      # Settings to improve lock handling and build performance
       use-case-hack = true;
       fallback = true;
       keep-going = true;
-      log-lines = 50;
-      connect-timeout = 10;
-      download-buffer-size = 65536; # 64MB download buffer
+      log-lines = 25;
+      download-buffer-size =
+        268435456; # 256MB download buffer (optimized for 16GB RAM)
+
+      # Substituter optimizations for 16GB RAM system
+      builders-use-substitutes = true;
+      http-connections = 50; # Increased for faster parallel downloads
+      max-substitution-jobs = 32; # Increased for better parallelization
+      stalled-download-timeout = 300; # 5 minutes timeout
+      connect-timeout = 30; # Optimized connection timeout
     };
 
     # Set up automatic store optimization

common/default.nix

@@ -0,0 +1,20 @@
+# Base Home Manager configuration shared across all platforms
+{ nixpkgs, ... }:
+
+{
+  # Allow unfree packages
+  nixpkgs.config.allowUnfree = true;
+
+  # Nix configuration with experimental features
+  nix = {
+    package = nixpkgs.legacyPackages.aarch64-linux.nix;
+    settings = {
+      experimental-features = [ "nix-command" "flakes" ];
+
+      # Additional performance settings
+      auto-optimise-store = false; # Let nix-darwin handle this
+      use-case-hack = true;
+      fallback = true;
+    };
+  };
+}