Fix gosec G602 slice bounds warning

Use range loop with explicit bounds check to satisfy stricter
gosec checks in golangci-lint 2.6.2.

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

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

Author: Claude

container/internal/tui/initialization_commands.go

@@ -56,10 +56,13 @@ func semverCompare(a, b string) int {
 		}
 		parts := strings.Split(s, ".")
 		result := make([]int, 3)
-		for i := 0; i < 3 && i < len(parts); i++ {
+		for i, part := range parts {
+			if i >= 3 {
+				break
+			}
 			// best-effort parse
 			n := 0
-			for _, ch := range parts[i] {
+			for _, ch := range part {
 				if ch >= '0' && ch <= '9' {
 					n = n*10 + int(ch-'0')
 				} else {