chore(nix): migrate lefthook from npm to nix (#294)

Move lefthook from pnpm devDependencies to nix flake buildInputs.
This ensures consistent versioning across the team via nix and
automatically installs git hooks when entering the devshell.

Changes:
- Add lefthook to flake.nix buildInputs
- Add `lefthook install` to shellHook for automatic setup
- Remove lefthook from package.json devDependencies
- Remove lefthook from pnpm-workspace.yaml catalog and onlyBuiltDependencies

Author: ryoppippi

flake.nix

@@ -37,6 +37,9 @@
 
               # security
               gitleaks
+
+              # git hooks
+              lefthook
             ];
 
             shellHook = ''
@@ -47,6 +50,9 @@
                 echo "📦 Installing dependencies..."
                 pnpm install --frozen-lockfile
               fi
+
+              # Install lefthook git hooks
+              lefthook install > /dev/null 2>&1
             '';
           };
         }

package.json

@@ -72,7 +72,6 @@
 		"ai": "catalog:dev",
 		"hono": "catalog:dev",
 		"knip": "catalog:dev",
-		"lefthook": "catalog:dev",
 		"msw": "catalog:dev",
 		"openai": "catalog:peer",
 		"publint": "catalog:dev",

pnpm-lock.yaml

@@ -16,7 +16,6 @@ catalogs:
     '@vitest/coverage-v8': ^4.0.15
     hono: ^4.9.10
     knip: ^5.72.0
-    lefthook: ^2.0.8
     msw: ^2.10.4
     publint: ^0.3.12
     tsdown: ^0.17.2
@@ -55,7 +54,6 @@ minimumReleaseAgeExclude:
 
 onlyBuiltDependencies:
   - esbuild
-  - lefthook
   - msw
 
 shellEmulator: true