Add regression test for PR #575 to ensure rate limit headers are formatted
as decimal strings (e.g., "10") instead of Unicode control characters.
Also fixes pre-existing fmt.Sprintf argument count mismatch in PVE setup
script (internal/api/config_handlers.go:3077). The template had 28 format
specifiers (excluding %%s escape sequence) but was only receiving 24
arguments. Added missing pulseURL and tokenName arguments to match template.
Related: #575
