Add WebSocket TLS and timeout recipes to the Cookbook

T04 (mTLS) had grown a "WebSocketClient" subsection describing
wss:// client certificates, and c12/t02 were getting similar
WebSocketClient asides for timeouts and CA paths. The Cookbook's
own index already separates WebSocket into its own category
(W01-W04) from TLS/Security (T01-T05) and Client (C01-C19), so
burying WebSocketClient specifics inside those pages fought the
site's structure.

Move that content into two new recipes under the WebSocket
category instead:

- W05: wss:// TLS setup (set_ca_cert_path CA directory parity,
  PemMemory client certificate)
- W06: WebSocketClient's three timeouts, including the recently
  added chrono overloads

T04, T02, C12, and W01 now carry a single reference link to the
new pages instead of duplicated explanations, matching the site's
existing cross-link convention.

While rewriting T04's client-side section, noticed it documented
SSLClient's file-path constructor but not its PemMemory one, even
though the server-side section covered both forms for SSLServer.
Added the missing PemMemory example so both sides are symmetric.

docs-src/pages/en/cookbook/w06-websocket-timeouts.md

@@ -0,0 +1,51 @@
+---
+title: "W06. Set Timeouts"
+order: 56
+status: "draft"
+---
+
+`ws::WebSocketClient` has the same three kinds of timeouts as `Client`, with the same meaning.
+
+| Kind | API | Default |
+| --- | --- | --- |
+| Connection | `set_connection_timeout` | 300s |
+| Read | `set_read_timeout` | 300s (`CPPHTTPLIB_WEBSOCKET_READ_TIMEOUT_SECOND`) |
+| Write | `set_write_timeout` | 5s |
+
+## Basic usage
+
+```cpp
+httplib::ws::WebSocketClient ws("ws://localhost:8080/ws");
+
+ws.set_connection_timeout(5, 0);  // 5 seconds
+ws.set_read_timeout(30, 0);       // 30 seconds
+ws.set_write_timeout(10, 0);      // 10 seconds
+
+if (ws.connect()) {
+  ws.send("hello");
+}
+```
+
+Set these before calling `connect()`.
+
+## Use `std::chrono`
+
+Just like `Client`, there's an overload that takes a `std::chrono` duration directly.
+
+```cpp
+using namespace std::chrono_literals;
+
+ws.set_connection_timeout(5s);
+ws.set_read_timeout(30s);
+ws.set_write_timeout(10s);
+```
+
+## Watch out for what the read timeout means
+
+`set_read_timeout()` applies to a single `read()` call. If no message arrives within that time, `read()` returns `ReadResult::Fail`. For connections where long idle periods are normal — waiting on notifications, for example — set a longer timeout, or reconnect from your application code when the read fails.
+
+> Unresponsive-peer detection via Ping/Pong is a separate mechanism. See [W02. Set a WebSocket Heartbeat](../w02-websocket-ping) for details.
+
+## How this differs from `Client`
+
+For `Client`'s timeout configuration, see [C12. Set Timeouts](../c12-timeouts). The behavior and API are nearly identical, but `WebSocketClient` has no equivalent to `set_max_timeout()` for capping the whole request — once connected, the connection stays open for as long as you keep calling `read()`.