fix: simplify branch name filtering to satisfy linter

Remove redundant HasPrefix check before TrimPrefix call. The
strings.TrimPrefix function is safe to call unconditionally as it
returns the original string if the prefix doesn't exist.

Fixes linter error: S1017: should replace this `if` statement with
an unconditional `strings.TrimPrefix` (gosimple)

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

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

Author: timvw

main.go

@@ -178,9 +178,7 @@ func getAvailableBranches() ([]string, error) {
 		}
 
 		// For remote branches, strip the origin/ prefix
-		if strings.HasPrefix(branch, "origin/") {
-			branch = strings.TrimPrefix(branch, "origin/")
-		}
+		branch = strings.TrimPrefix(branch, "origin/")
 
 		// Skip if branch name is just "origin" or other remote names
 		if branch == "origin" || branch == "upstream" {