Fix remaining errcheck warnings in daemon.go, daemon_lock.go, delete.go

- daemon.go: fix os.Remove() in stopDaemon (line 602)
- daemon_lock.go: fix f.Close() and fmt.Fprintf() calls
- delete.go: fix cmd.Usage(), out.Close(), and os.Remove() calls

All error returns now properly handled or explicitly ignored.

Amp-Thread-ID: https://ampcode.com/threads/T-56b6d9f4-16a4-4c50-b7b9-dde1c3774650
Co-authored-by: Amp <amp@ampcode.com>

cmd/bd/daemon.go

@@ -599,7 +599,7 @@ func stopDaemon(pidFile string) {
 				fmt.Fprintf(os.Stderr, "Error killing process: %v\n", err)
 			}
 		}
-		os.Remove(pidFile)
+		_ = os.Remove(pidFile)
 		fmt.Println("Daemon killed")
 	}
 }

cmd/bd/daemon_lock.go

@@ -41,7 +41,7 @@ func acquireDaemonLock(beadsDir string, global bool) (*DaemonLock, error) {
 
 	// Try to acquire exclusive non-blocking lock
 	if err := flockExclusive(f); err != nil {
-		f.Close()
+		_ = f.Close()
 		if err == ErrDaemonLocked {
 			return nil, ErrDaemonLocked
 		}
@@ -51,7 +51,7 @@ func acquireDaemonLock(beadsDir string, global bool) (*DaemonLock, error) {
 	// Write our PID to the lock file for debugging (optional)
 	_ = f.Truncate(0)
 	_, _ = f.Seek(0, 0)
-	fmt.Fprintf(f, "%d\n", os.Getpid())
+	_, _ = fmt.Fprintf(f, "%d\n", os.Getpid())
 	_ = f.Sync()
 
 	// Also write PID file for Windows compatibility (can't read locked files on Windows)
@@ -74,7 +74,7 @@ func tryDaemonLock(beadsDir string) (running bool, pid int) {
 		// Fall back to PID file check for backward compatibility
 		return checkPIDFile(beadsDir)
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	// Try to acquire lock non-blocking
 	if err := flockExclusive(f); err != nil {

cmd/bd/delete.go

@@ -70,7 +70,7 @@ Force: Delete and orphan dependents
 
 		if len(issueIDs) == 0 {
 			fmt.Fprintf(os.Stderr, "Error: no issue IDs provided\n")
-			cmd.Usage()
+			_ = cmd.Usage()
 			os.Exit(1)
 		}
 
@@ -353,8 +353,8 @@ func removeIssueFromJSONL(issueID string) error {
 	enc := json.NewEncoder(out)
 	for _, iss := range issues {
 		if err := enc.Encode(iss); err != nil {
-			out.Close()
-			os.Remove(temp)
+			_ = out.Close()
+			_ = os.Remove(temp)
 			return fmt.Errorf("failed to write issue: %w", err)
 		}
 	}