Unbitch flake.nix - extract shell scripts to separate files

- Moved all inline shell scripts to packages/scripts/
- Created packages/default.nix for clean package definitions
- Reduced flake.nix from 400+ lines to ~80 lines
- Maintained all functionality while improving maintainability
- All builds and checks still pass

packages/scripts/test-quickshell.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+echo "🧪 Testing quickshell with dots-hyprland config..."
+
+if [[ ! -d "$HOME/.config/quickshell" ]]; then
+  echo "❌ No quickshell configuration found"
+  echo "💡 Run: home-manager switch"
+  exit 1
+fi
+
+cd "$HOME/.config/quickshell"
+echo "🚀 Starting quickshell (timeout 10s)..."
+timeout 10 quickshell 2>&1 | head -20