fix(webchat): align WebSocket payload limit with agent response buffer

src/channels/webchat.c

@@ -25,7 +25,7 @@ static int webchat_poll(channel_incoming_msg_t *out, int timeout_ms)
 	if (!out) return -1;
 	memset(out, 0, sizeof(*out));
 	char session_id[128];
-	char text[8192];
+	char text[WS_TEXT_MAX];
 	int r = ws_pop_incoming(session_id, sizeof(session_id), text, sizeof(text), timeout_ms);
 	if (r != 1) return r;
 	out->session_id = strdup(session_id);

src/gateway/http_lws.c

@@ -493,10 +493,10 @@ int ws_callback(struct lws *wsi, enum lws_callback_reasons reason, void *user,
 	case LWS_CALLBACK_SERVER_WRITEABLE: {
 		int conn_id = (int)(intptr_t)lws_wsi_user(wsi);
 		if (conn_id <= 0) break;
-		char buf[8192];
+		char buf[WS_TEXT_MAX];
 		size_t len_out = 0;
 		if (ws_dequeue_outgoing(conn_id, buf, sizeof(buf), &len_out)) {
-			unsigned char frame[LWS_PRE + 8192];
+			unsigned char frame[LWS_PRE + WS_TEXT_MAX];
 			if (len_out < sizeof(frame) - LWS_PRE) {
 				memcpy(frame + LWS_PRE, buf, len_out);
 				if (lws_write(wsi, frame + LWS_PRE, len_out, LWS_WRITE_TEXT) < 0)

src/gateway/ws.c

@@ -23,14 +23,12 @@ static void lws_callback_on_writable(struct lws *wsi) { (void)wsi; }
 
 #define MAX_CONNECTIONS 16
 #define MAX_QUEUE 64
-#define MSG_MAX 8192
-
 static size_t ws_text_len_ok(const char *text)
 {
 	size_t len;
 	if (!text) return 0;
 	len = strlen(text);
-	return len > 0 && len <= (size_t)MSG_MAX;
+	return len > 0 && len <= (size_t)WS_TEXT_MAX;
 }
 
 typedef struct ws_msg {

src/gateway/ws.h

@@ -12,6 +12,9 @@
 extern "C" {
 #endif
 
+/** Max WebSocket text payload (matches RESPONSE_BUF_SIZE in dispatch.c). */
+#define WS_TEXT_MAX (32 * 1024)
+
 /** Opaque WebSocket connection handle (lws wsi cast to void*). */
 typedef void *ws_conn_t;
 

tests/test_ws.c

@@ -24,8 +24,27 @@
 			return _r;                                                             \
 	} while (0)
 
-/** Must match MSG_MAX in src/gateway/ws.c */
-#define WS_MSG_MAX 8192
+/** Must match WS_TEXT_MAX in src/gateway/ws.h */
+
+static int test_send_to_accepts_dispatch_sized_payload(void)
+{
+	char *payload;
+	char buf[WS_TEXT_MAX];
+	size_t len_out;
+	ws_cleanup();
+	ASSERT(ws_register_conn(3, (ws_conn_t)(intptr_t)3) == 0);
+	payload = malloc(10000);
+	ASSERT(payload != NULL);
+	memset(payload, 'c', 9999);
+	payload[9999] = '\0';
+	ASSERT(ws_send_to("webchat:3", payload) == 0);
+	ASSERT(ws_dequeue_outgoing(3, buf, sizeof(buf), &len_out) == 1);
+	ASSERT(len_out == 9999);
+	ASSERT(memcmp(buf, payload, 9999) == 0);
+	free(payload);
+	ws_cleanup();
+	return 0;
+}
 
 static int test_register_conn_full_table(void)
 {
@@ -46,10 +65,10 @@ static int test_push_incoming_msg_max(void)
 	int got;
 	ws_cleanup();
 	ASSERT(ws_register_conn(1, (ws_conn_t)(intptr_t)1) == 0);
-	big = malloc((size_t)WS_MSG_MAX + 2);
+	big = malloc((size_t)WS_TEXT_MAX + 2);
 	ASSERT(big != NULL);
-	memset(big, 'a', (size_t)WS_MSG_MAX + 1);
-	big[WS_MSG_MAX + 1] = '\0';
+	memset(big, 'a', (size_t)WS_TEXT_MAX + 1);
+	big[WS_TEXT_MAX + 1] = '\0';
 	ws_push_incoming(1, big);
 	got = ws_pop_incoming(session, sizeof(session), text, sizeof(text), 50);
 	ASSERT(got == 0);
@@ -67,10 +86,10 @@ static int test_send_to_rejects_oversized(void)
 	char *big;
 	ws_cleanup();
 	ASSERT(ws_register_conn(2, (ws_conn_t)(intptr_t)2) == 0);
-	big = malloc((size_t)WS_MSG_MAX + 2);
+	big = malloc((size_t)WS_TEXT_MAX + 2);
 	ASSERT(big != NULL);
-	memset(big, 'b', (size_t)WS_MSG_MAX + 1);
-	big[WS_MSG_MAX + 1] = '\0';
+	memset(big, 'b', (size_t)WS_TEXT_MAX + 1);
+	big[WS_TEXT_MAX + 1] = '\0';
 	ASSERT(ws_send_to("webchat:2", big) != 0);
 	ASSERT(ws_send_to("webchat:2", "hi") == 0);
 	free(big);
@@ -83,6 +102,7 @@ int main(void)
 	RUN(test_register_conn_full_table());
 	RUN(test_push_incoming_msg_max());
 	RUN(test_send_to_rejects_oversized());
+	RUN(test_send_to_accepts_dispatch_sized_payload());
 	printf("test_ws: all tests passed\n");
 	return 0;
 }