fix: exclude WebSocket from rate limiting to prevent UI lockout

The /ws endpoint was rate limited to 30 connections/minute. After
prolonged use with WebSocket reconnections (network hiccups, browser
tab throttling, etc.), users with many Docker containers would hit
this limit and get stuck with a 'Connecting...' UI.

WebSocket connections are already authenticated via session/API token
and reconnections are normal behavior, so rate limiting is not needed.

Fixes #859 (second report about WebSocket rate limiting after hours of use).

internal/api/rate_limit_config.go

@@ -136,6 +136,7 @@ func UniversalRateLimitMiddleware(next http.Handler) http.Handler {
 		skipPaths := []string{
 			"/api/state",           // Real-time state updates
 			"/api/guests/metadata", // Guest metadata (polled frequently)
+			"/ws",                  // WebSocket connections (authenticated, reconnections are normal)
 		}
 		for _, path := range skipPaths {
 			if strings.Contains(r.URL.Path, path) {