[eric] browser: re-broadcast ws commands lost in dead-socket gaps, refetch layout on reconnect

backend/tests/test_browser_command_timeout.py

@@ -58,6 +58,28 @@ async def test_navigate_gets_the_longer_leash(monkeypatch):
     assert elapsed > 0.5, "navigate should use its longer bound, not the default"
 
 
+@pytest.mark.asyncio
+async def test_lost_first_delivery_heals_via_rebroadcast(monkeypatch):
+    # a silently-dead socket eats the first broadcast; the re-send after the
+    # rebroadcast interval must reach the (reconnected) client and succeed
+    monkeypatch.setattr(wsm, "_BROWSER_CMD_TIMEOUT_DEFAULT", 5.0)
+    monkeypatch.setattr(wsm, "_BROWSER_CMD_REBROADCAST_S", 0.1)
+    m = _mgr()
+    sends = []
+
+    class _CountingSock:
+        async def send_text(self, payload):
+            sends.append(payload)
+            if len(sends) >= 2:  # first delivery "lost", second lands
+                rid = next(iter(m.browser_futures))
+                m.resolve_browser_command(rid, {"text": "ok"})
+
+    m.global_connections = [_CountingSock()]
+    res = await m.send_browser_command("rid4", "get_text", "b1", {})
+    assert res == {"text": "ok"}
+    assert len(sends) >= 2, "command must be re-broadcast until a client answers"
+
+
 @pytest.mark.asyncio
 async def test_a_resolved_command_returns_immediately(monkeypatch):
     # a healthy command returns the moment the renderer resolves it, not at the bound