Implement hybrid package management: stable + selective unstable

- Add nixpkgs-unstable input to flake.nix
- Configure specialArgs to pass pkgs-unstable to all system configs
- Update desktop/dev.nix to use windsurf from unstable packages
- Create comprehensive documentation in README-hybrid-packages.md
- Enable selective use of cutting-edge packages while maintaining system stability

Usage: Add pkgs-unstable parameter to any .nix file and use pkgs-unstable.package-name
Example: pkgs-unstable.windsurf for latest Windsurf editor

README-hybrid-packages.md

@@ -0,0 +1,117 @@
+# Hybrid Package Management: Stable + Unstable
+
+This NixOS configuration uses a hybrid approach where the system runs on the stable NixOS 24.05 branch but can selectively use packages from the unstable branch when needed.
+
+## How It Works
+
+The `flake.nix` includes both stable and unstable nixpkgs inputs:
+
+```nix
+inputs = {
+  nixpkgs.url = "nixpkgs/nixos-24.05";           # Stable base
+  nixpkgs-unstable.url = "nixpkgs/nixos-unstable"; # Unstable packages
+  # ... other inputs
+};
+```
+
+The unstable packages are made available to all system configurations via `specialArgs`:
+
+```nix
+nixosConfigurations = {
+  framework = nixpkgs.lib.nixosSystem {
+    system = "x86_64-linux";
+    specialArgs = {
+      pkgs-unstable = import nixpkgs-unstable {
+        system = "x86_64-linux";
+        config.allowUnfree = true;
+      };
+    };
+    modules = [ /* ... */ ];
+  };
+};
+```
+
+## Using Unstable Packages
+
+### In System Configuration Files
+
+To use an unstable package in any `.nix` configuration file:
+
+1. **Add `pkgs-unstable` to the function parameters:**
+   ```nix
+   { config, pkgs, pkgs-unstable, ... }:
+   ```
+
+2. **Use the unstable package:**
+   ```nix
+   environment.systemPackages = with pkgs; [
+     # Stable packages
+     firefox
+     git
+     
+     # Unstable packages
+     pkgs-unstable.windsurf
+     pkgs-unstable.some-other-package
+   ];
+   ```
+
+### Example: Current Usage
+
+See `desktop/dev.nix` for a working example:
+
+```nix
+{ config, pkgs, pkgs-unstable, ... }:
+
+{
+  environment.systemPackages = with pkgs; [
+    # Stable packages
+    nodejs
+    rpi-imager
+    
+    # Unstable packages
+    pkgs-unstable.windsurf  # Use windsurf from unstable
+  ];
+}
+```
+
+## When to Use Unstable Packages
+
+Use unstable packages when:
+- A package is not available in the stable branch
+- You need a newer version with specific features or bug fixes
+- You're developing with cutting-edge tools
+
+## Benefits of This Approach
+
+1. **System Stability**: Core system components use stable, well-tested packages
+2. **Package Availability**: Access to the latest packages when needed
+3. **Selective Updates**: Choose which packages to get from unstable
+4. **Easy Maintenance**: Clear separation between stable and unstable dependencies
+
+## Adding New Unstable Packages
+
+To add a new unstable package:
+
+1. Find the configuration file where you want to add the package
+2. Ensure the file accepts `pkgs-unstable` parameter
+3. Add `pkgs-unstable.package-name` to the appropriate list
+4. Test with `nixos-rebuild dry-run --flake .#framework`
+5. Apply with `nixos-rebuild switch --flake .#framework`
+
+## Updating Packages
+
+- **Stable packages**: Updated when you update the flake lock
+- **Unstable packages**: Updated when you run `nix flake update`
+
+To update only unstable packages:
+```bash
+nix flake lock --update-input nixpkgs-unstable
+```
+
+## Current Unstable Packages in Use
+
+- `windsurf` - Modern code editor (in `desktop/dev.nix`)
+
+---
+
+This hybrid approach gives you the stability of NixOS stable with the flexibility to use cutting-edge packages when needed.

desktop/dev.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ config, pkgs, pkgs-unstable, ... }:
 
 {
 
@@ -6,6 +6,7 @@ environment.systemPackages = with pkgs; [
    (python3.withPackages(ps: with ps; [ pandas requests python-dotenv pip uv ]))
   nodejs
   rpi-imager
+  pkgs-unstable.windsurf  # Use windsurf from unstable packages
   ];
 
 programs.nix-ld.enable = true;

flake.lock

@@ -52,6 +52,21 @@
         "type": "indirect"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1753694789,
+        "narHash": "sha256-cKgvtz6fKuK1Xr5LQW/zOUiAC0oSQoA9nOISB0pJZqM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "dc9637876d0dcc8c9e5e22986b857632effeb727",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
     "plasma-manager": {
       "inputs": {
         "home-manager": [
@@ -80,6 +95,7 @@
         "home-manager": "home-manager",
         "nixos-hardware": "nixos-hardware",
         "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable",
         "plasma-manager": "plasma-manager"
       }
     }

flake.nix

@@ -3,6 +3,7 @@
 
   inputs = {
     nixpkgs.url = "nixpkgs/nixos-24.05";
+    nixpkgs-unstable.url = "nixpkgs/nixos-unstable";
     nixos-hardware.url = "github:NixOS/nixos-hardware/master";
     home-manager = {
       url = "github:nix-community/home-manager/release-24.05";
@@ -15,10 +16,16 @@
     };
   };
 
-  outputs = { self, nixpkgs, nixos-hardware, home-manager, plasma-manager }: {
+  outputs = { self, nixpkgs, nixpkgs-unstable, nixos-hardware, home-manager, plasma-manager }: {
     nixosConfigurations = {
       framework =  nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
+        specialArgs = {
+          pkgs-unstable = import nixpkgs-unstable {
+            system = "x86_64-linux";
+            config.allowUnfree = true;
+          };
+        };
         modules = [
           home-manager.nixosModules.home-manager
           nixos-hardware.nixosModules.framework-16-7040-amd
@@ -36,6 +43,12 @@
       };
       aurora = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
+        specialArgs = {
+          pkgs-unstable = import nixpkgs-unstable {
+            system = "x86_64-linux";
+            config.allowUnfree = true;
+          };
+        };
         modules = [
           home-manager.nixosModules.home-manager
           ./systems/common.nix