chore(clients): roll out feed-level snapshot_status to all five clients

Task 1 added AlarmSnapshotStatus and AlarmFeedMessage.snapshot_status = 5.
Carry it downstream from the canonical Contracts protos:

- Rust vendored protos under clients/rust/protos, refreshed byte-identical
  (build.rs falls back to them for out-of-repo tarball builds)
- client descriptor set (protoc 34.1 pin)
- Go (protoc-gen-go v1.36.11 / protoc-gen-go-grpc 1.6.2)
- Python (grpcio-tools 1.80.0 pin)
- Java (gradle generateProto)

.NET needs no regeneration: the client compiles against the Contracts
Generated/ output committed with the proto change.

The hand-written CLI feed renderers switch on the payload oneof, so codegen
alone does not carry the arm. Add snapshot-status to the .NET, Go, Rust, and
Java renderers; the .NET and Go renderers were also missing provider-status,
which has been on the wire since the provider-mode work, so add it there too.
Java's renderer is an exhaustive switch expression and did not compile until
the new case landed. The Python CLI renders generic protobuf-JSON and needs
no change.

Each client README gains a paragraph on the feed-level frame next to its
existing from_truncated_snapshot paragraph: it arrives at stream open after
provider_status and before the cached active_alarm frames, then on every
verdict change including the clearing frame a monitor restart emits, so a
live consumer can track set completeness without polling QueryActiveAlarms.

GatewayDashboardDesign: list the two new payload cases the AlarmsHub forwards,
and — separately — record the GroupToRole / GroupToTag / UntaggedSessionVisibility
rows the settings page already renders but the bullet list omitted.

clients/dotnet/ZB.MOM.WW.MxGateway.Client.Cli/MxGatewayClientCli.cs

@@ -1546,8 +1546,9 @@ public static class MxGatewayClientCli
     /// <summary>
     /// Renders one <see cref="AlarmFeedMessage"/> for the human-readable
     /// (non-JSON) stream-alarms output, distinguishing the <c>payload</c> oneof
-    /// arms: a snapshot active alarm, the snapshot-complete sentinel, or a live
-    /// transition.
+    /// arms: a snapshot active alarm, the snapshot-complete sentinel, a live
+    /// transition, the provider-mode status, or the feed-level
+    /// snapshot-completeness status.
     /// </summary>
     private static string FormatAlarmFeedMessage(AlarmFeedMessage feedMessage)
     {
@@ -1559,6 +1560,10 @@ public static class MxGatewayClientCli
                 $"snapshot-complete {feedMessage.SnapshotComplete}",
             AlarmFeedMessage.PayloadOneofCase.Transition =>
                 $"transition {ProtobufJsonFormatter.Format(feedMessage.Transition)}",
+            AlarmFeedMessage.PayloadOneofCase.ProviderStatus =>
+                $"provider-status {ProtobufJsonFormatter.Format(feedMessage.ProviderStatus)}",
+            AlarmFeedMessage.PayloadOneofCase.SnapshotStatus =>
+                $"snapshot-status {ProtobufJsonFormatter.Format(feedMessage.SnapshotStatus)}",
             _ => $"unknown-payload {feedMessage.PayloadCase}",
         };
     }