feat: Initial commit

shell.nix

@@ -0,0 +1,56 @@
+{pkgs ? import <nixpkgs> {}}:
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    # Build dependencies
+    nix
+    nix-prefetch-github
+
+    # Runtime dependencies for testing
+    nautilus
+    nautilus-python
+    ffmpeg
+    python3
+
+    # Python packages for development
+    (python3.withPackages (ps:
+      with ps; [
+        pillow
+        python-magic
+        pygobject3
+        pillow-heif
+      ]))
+
+    # GTK/GObject development
+    gtk3
+    gobject-introspection
+    wrapGAppsHook3
+
+    # Testing and validation
+    file
+    tree
+  ];
+
+  shellHook = ''
+    echo "Linux File Converter Addon - Development Environment"
+    echo "==================================================="
+    echo ""
+    echo "Available commands:"
+    echo "  nix-build              - Build the package"
+    echo "  nix-build test.nix     - Run test suite"
+    echo "  nix-prefetch-github    - Update source hash"
+    echo ""
+    echo "Package files:"
+    echo "  package.nix   - Main package definition"
+    echo "  default.nix   - Simple builder"
+    echo "  test.nix      - Test suite"
+    echo "  shell.nix     - This development environment"
+    echo ""
+    echo "To test build: nix-build && tree result/"
+    echo "To run tests:  nix-build test.nix && ./result/bin/test-linux-file-converter-addon"
+    echo ""
+  '';
+
+  # Environment variables for development
+  NIX_SHELL_PRESERVE_PROMPT = 1;
+  NIXPKGS_ALLOW_UNFREE = 1;
+}