feat(packages): add desloppify v0.9.15

Add desloppify, a multi-language codebase health scanner and technical
debt tracker for AI agents. Includes all [full] optional dependencies
(tree-sitter, bandit, pillow, pyyaml, defusedxml) for complete
functionality out of the box.

packages/desloppify/default.nix

@@ -0,0 +1 @@
+{ pkgs, ... }: pkgs.callPackage ./package.nix { }

packages/desloppify/package.nix

@@ -0,0 +1,54 @@
+{
+  lib,
+  python3Packages,
+  fetchFromGitHub,
+}:
+
+python3Packages.buildPythonApplication rec {
+  pname = "desloppify";
+  version = "0.9.15";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "peteromallet";
+    repo = "desloppify";
+    rev = "v${version}";
+    hash = "sha256-KVCt9loGSzsOaYSLNzpyUCi/TpCDQ4b6BxEydQTRNcA=";
+  };
+
+  build-system = with python3Packages; [
+    setuptools
+  ];
+
+  # Include all [full] optional dependencies for complete functionality.
+  # Upstream has no base dependencies - all features are behind optional extras.
+  dependencies = with python3Packages; [
+    tree-sitter
+    tree-sitter-language-pack
+    defusedxml
+    bandit
+    pillow
+    pyyaml
+  ];
+
+  doCheck = false;
+  pythonImportsCheck = [ "desloppify" ];
+
+  passthru = {
+    category = "AI Coding Agents";
+    updateScript = [
+      "nix-update"
+      "--flake"
+      ".#desloppify"
+    ];
+  };
+
+  meta = {
+    description = "Multi-language codebase health scanner and technical debt tracker for AI agents";
+    homepage = "https://github.com/peteromallet/desloppify";
+    changelog = "https://github.com/peteromallet/desloppify/releases/tag/v${version}";
+    license = lib.licenses.unfreeRedistributable;
+    mainProgram = "desloppify";
+    platforms = lib.platforms.all;
+  };
+}