feat: add git-hooks.nix pre-commit checks to flake

Add cachix/git-hooks.nix input and wire basedpyright, ruff,
ruff-format, and commitizen hooks into flake checks and devShell.
The basedpyright hook runs against a Nix-built venv so imports
resolve correctly in the sandbox.

flake.lock

@@ -1,5 +1,64 @@
 {
   "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1767039857,
+        "narHash": "sha256-vNpUSpF5Nuw8xvDLj2KCwwksIbjua2LZCqhV1LNRDns=",
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "rev": "5edf11c44bc78a0d334f6334cdaf7d60d732daab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1770726378,
+        "narHash": "sha256-kck+vIbGOaM/dHea7aTBxdFYpeUl/jHOy5W3eyRvVx8=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "5eaaedde414f6eb1aea8b8525c466dc37bba95ae",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "git-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1770841267,
@@ -64,6 +123,7 @@
     },
     "root": {
       "inputs": {
+        "git-hooks": "git-hooks",
         "nixpkgs": "nixpkgs",
         "pyproject-build-systems": "pyproject-build-systems",
         "pyproject-nix": "pyproject-nix",