fix: resolve all remaining errcheck violations for complete CI compliance

- Fixed unchecked conn.Close() in pool shutdown and connection cleanup
- Fixed unchecked conn.Close() in worker socket readiness check
- Added errcheck to local linter configuration for consistency

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: YuminosukeSato

.golangci.yml

@@ -9,6 +9,7 @@ linters:
     - goimports
     - revive
     - misspell
+    - errcheck
 
 issues:
   exclude-use-default: false

pkg/pyproc/pool.go

@@ -256,7 +256,7 @@ func (p *Pool) Shutdown(_ context.Context) error {
 	for _, pw := range p.workers {
 		close(pw.connPool)
 		for conn := range pw.connPool {
-			conn.Close()
+			_ = conn.Close()
 		}
 	}
 
@@ -299,7 +299,7 @@ func (w *Worker) IsHealthy(ctx context.Context) bool {
 	if err != nil {
 		return false
 	}
-	conn.Close()
+	_ = conn.Close()
 	return true
 }
 

pkg/pyproc/worker.go

@@ -119,7 +119,7 @@ func (w *Worker) Start(ctx context.Context) error {
 				// Try to connect to the socket
 				conn, err := net.Dial("unix", w.cfg.SocketPath)
 				if err == nil {
-					conn.Close()
+					_ = conn.Close()
 					socketReady <- nil
 					return
 				}