fix(loro-websocket): default ping interval to 20s

llms.md

@@ -197,7 +197,7 @@ Adaptors bridge the client to actual CRDT state:
 ```ts
 new LoroWebsocketClient({
   url: string,                 // Required ws:// or wss:// endpoint.
-  pingIntervalMs?: number,     // Default 30_000 ms.
+  pingIntervalMs?: number,     // Default 20_000 ms.
   disablePing?: boolean,       // Skip periodic ping/pong entirely.
   onWsClose?: () => void,      // Invoked on low-level close before status change.
 });

packages/loro-websocket/README.md

@@ -68,7 +68,7 @@ new LoroWebsocketClient(options: LoroWebsocketClientOptions)
 
 interface LoroWebsocketClientOptions {
   url: string;                 // WebSocket URL (ws:// or wss://)
-  pingIntervalMs?: number;     // Periodic ping interval (default 30_000ms)
+  pingIntervalMs?: number;     // Periodic ping interval (default 20_000ms)
   disablePing?: boolean;       // Disable periodic pings entirely
   onWsClose?: () => void;      // Low‑level ws close callback (before status transitions)
 }
@@ -117,7 +117,7 @@ type ClientStatusValue = typeof ClientStatus[keyof typeof ClientStatus];
 ## Latency & Ping/Pong
 
 - Periodic pings
-  - By default, the client sends a text `"ping"` every 30s (configurable via `pingIntervalMs`) and expects a `"pong"`. This keeps the connection alive and measures round‑trip latency.
+  - By default, the client sends a text `"ping"` every 20s (configurable via `pingIntervalMs`) and expects a `"pong"`. This keeps the connection alive and measures round‑trip latency.
   - Set `disablePing: true` to turn off the timer.
 
 - On‑demand ping

packages/loro-websocket/src/client/index.ts

@@ -98,7 +98,7 @@ export type ClientStatusValue =
 export interface LoroWebsocketClientOptions {
   /** WebSocket URL (ws:// or wss://). */
   url: string;
-  /** Optional custom ping interval. Defaults to 30s. Set with `disablePing` to stop timers. */
+  /** Optional custom ping interval. Defaults to 20s. Set with `disablePing` to stop timers. */
   pingIntervalMs?: number;
   /** Ping timeout; after two consecutive misses the client will force-close and reconnect. Defaults to 10s. */
   pingTimeoutMs?: number;
@@ -1733,15 +1733,15 @@ function isPositive(v: unknown): v is number {
   return typeof v === "number" && isFinite(v) && v > 0;
 }
 
-// Use default 30s unless disabled
+// Use default 20s unless disabled
 function getPingIntervalMs(opts: {
   pingIntervalMs?: number;
   disablePing?: boolean;
 }): number | undefined {
   if (opts.disablePing) return undefined;
   const v = opts.pingIntervalMs;
   if (isPositive(v)) return v;
-  return 30_000;
+  return 20_000;
 }
 
 function createLoroWebsocketClientRoom(opts: {