fix(focas): serialize per-device wire I/O + bound reads; tolerate AdminUI config formats

Equipment tags were stuck at Bad_WaitingForInitialData on the deployed driver: the equipment poll, fixed-tree loop, probe and recycle shared one FOCAS/2 socket with no serialization, and the steady-state read had no timeout — concurrent reads collided and a stalled read hung forever, never overwriting the node's initial-data seed.

- SynchronizedFocasClient: per-device SemaphoreSlim gate + per-call timeout around every wire op (Connect/Probe gated, not double-bounded); wired in EnsureConnectedAsync. ReadAsync/WriteAsync map a per-call timeout to BadCommunicationError instead of rethrowing.
- FlexibleStringConverter on FOCAS config Series: the AdminUI persists the enum as a number ("series":6); accept number-or-string instead of throwing -> stub.
- FocasHostAddress.TryParse tolerates a scheme-less {ip}[:{port}] (AdminUI hostAddress form); canonical focas:// unchanged, malformed schemes still rejected.

247 FOCAS tests green; each fix has a regression test. Live-validated on wonder-app-vd03 (tags read Good).

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/FocasScaffoldingTests.cs

@@ -20,6 +20,9 @@ public sealed class FocasScaffoldingTests
     [InlineData("focas://cnc-01.factory.internal:8193", "cnc-01.factory.internal", 8193)]
     [InlineData("focas://10.0.0.5:12345", "10.0.0.5", 12345)]
     [InlineData("FOCAS://10.0.0.5:8193", "10.0.0.5", 8193)]                    // case-insensitive scheme
+    [InlineData("10.201.31.5:8193", "10.201.31.5", 8193)]                     // scheme-less (AdminUI-persisted form)
+    [InlineData("10.0.0.5", "10.0.0.5", 8193)]                                // scheme-less, default port
+    [InlineData("cnc-01.factory.internal:8193", "cnc-01.factory.internal", 8193)] // scheme-less hostname
     public void HostAddress_parses_valid(string input, string host, int port)
     {
         var parsed = FocasHostAddress.TryParse(input);
@@ -224,9 +227,11 @@ public sealed class FocasScaffoldingTests
     [Fact]
     public async Task InitializeAsync_malformed_address_faults()
     {
+        // A non-focas:// URI scheme is rejected by TryParse (a bare "{ip}[:{port}]" is now
+        // tolerated, so the malformed case must carry a foreign scheme).
         var drv = new FocasDriver(new FocasDriverOptions
         {
-            Devices = [new FocasDeviceOptions("not-an-address")],
+            Devices = [new FocasDeviceOptions("http://10.0.0.5/")],
         }, "drv-1");
 
         await Should.ThrowAsync<InvalidOperationException>(