fix(retry): address PR #12 code review feedback

- Add 'stepped' backoff strategy that uses RETRY_BACKOFF_DELAYS directly
- Update rsocket config to use 'stepped' instead of 'exponential'
- Clarify maxWebSocketListeners calculation (8 core + 10 dynamic + 2 buffer)
- Document maxSocketClientListeners calculation (20 core + 20 dynamic + 10 buffer)
- Change 'exponential backoff' to 'custom progressive backoff' in docs
- Add comprehensive tests for getRetryDelayWithJitter and getAllRetryDelaysWithJitter
- Fix existing test type errors (onRetry mock, always/never predicates)

src/Defaults/index.ts

@@ -82,8 +82,13 @@ export const DEFAULT_CONNECTION_CONFIG: SocketConfig = {
 	// Circuit breaker configuration
 	enableCircuitBreaker: true,
 	// Listener limits (memory leak prevention)
-	// 8 base WS events + 10 dynamic listeners + 2 buffer slots
+	// WebSocket: 8 core events (open, close, error, message, ping, pong, upgrade, unexpected-response)
+	//          + 10 dynamic listeners (reconnect handlers, custom events)
+	//          + 2 buffer slots for temporary listeners = 20 total
 	maxWebSocketListeners: 20,
+	// SocketClient: 20 core events (connection, messaging, presence, groups, calls, etc.)
+	//             + 20 dynamic listeners (user handlers, plugins)
+	//             + 10 buffer slots for high-load scenarios = 50 total
 	maxSocketClientListeners: 50
 }
 
@@ -165,8 +170,9 @@ export const DEFAULT_CACHE_MAX_KEYS = {
 }
 
 /**
- * Retry configuration with exponential backoff
- * Delays in milliseconds: 1s, 2s, 5s, 10s, 20s
+ * Retry configuration with custom progressive backoff
+ * Fixed delay steps in milliseconds: 1s → 2s → 5s → 10s → 20s
+ * Use with 'stepped' backoff strategy in retry-utils.ts
  */
 export const RETRY_BACKOFF_DELAYS = [1000, 2000, 5000, 10000, 20000]