fix(dev): add reuse linter

We use this for our CI checks but for some reason not locally. Add it to
our pyproject and Nix shell, and create a pre-commit step for it.

.pre-commit-config.yaml

@@ -4,6 +4,11 @@
 repos:
   - repo: local
     hooks:
+      - id: reuse
+        name: reuse
+        entry: reuse lint-file
+        language: system
+
       - id: pyright
         name: pyright
         entry: pyright

nix/shell.nix

@@ -118,7 +118,7 @@ pkgs.mkShellNoCC {
 
       if [ ! -f "''${venv}"/pyproject.toml ] || ! diff --brief pyproject.toml "''${venv}"/pyproject.toml >/dev/null; then
           printf '%s\n' 'Installing dependencies, pyproject.toml changed...' >&2
-          uv pip install --quiet --editable . --group docs --group extra --group test
+          uv pip install --quiet --editable . --group docs --group extra --group reuse --group test
           cp pyproject.toml "''${venv}"/pyproject.toml
       fi
 

pyproject.toml

@@ -57,7 +57,11 @@ check = [{ include-group = "lint" }, { include-group = "test" }]
 build = [{ include-group = "pyinstaller" }]
 docs = [{ include-group = "mkdocs" }]
 extra = [{ include-group = "pre-commit" }]
-lint = [{ include-group = "pyright" }, { include-group = "ruff" }]
+lint = [
+    { include-group = "pyright" },
+    { include-group = "reuse" },
+    { include-group = "ruff" },
+]
 test = [{ include-group = "pytest" }]
 
 mkdocs = [
@@ -75,6 +79,7 @@ pytest = [
     "pytest-qt==4.4.0",
     "syrupy==5.1.0",
 ]
+reuse = ["reuse==6.*"]
 ruff = ["ruff==0.15.17"]
 
 [tool.hatch.build.targets.wheel]