clients: document supervisory/array-write parity gotchas and add advise-supervisory to all CLIs

A consuming project hit two MXAccess parity surprises: a plain Write only
records its user_id when the item has an active supervisory advise (the path
to take when not authenticating), and array writes replace the whole array
rather than patching individual elements. Document both across the five client
READMEs and gateway.md's compatibility baseline, and expose the missing
advise-supervisory subcommand in the go/python/rust/java CLIs (plus the .NET
help text) so callers can establish the supervisory advise without dropping to
the raw command API.

clients/python/README.md

@@ -105,6 +105,49 @@ terminate the stream.
 Canceling a Python task cancels the client-side gRPC call or stream wait. It
 does not abort an in-flight MXAccess COM call inside the worker process.
 
+## Write Semantics And Common Pitfalls
+
+These are MXAccess parity behaviors that surprise new callers. The gateway
+forwards them unchanged — it does not paper over them.
+
+### Attributing a write to a user without `authenticate_user`
+
+MXAccess only stamps a plain `write`/`write2` with a Galaxy user id when the
+item carries an active *supervisory* advise. If you are **not** using the
+verified/secured path (`authenticate_user` → `write_secured`/`write_secured2`)
+but still need the write attributed to a user id, you must first advise the
+item supervisory and then pass that user id on the write. Without the
+supervisory advise the `user_id` on a plain write is ignored.
+
+The session exposes `advise`/`unadvise` but not supervisory advise, so send it
+through the generic command channel:
+
+```python
+await session.invoke(
+    pb.MxCommand(
+        kind=pb.MX_COMMAND_KIND_ADVISE_SUPERVISORY,
+        advise_supervisory=pb.AdviseSupervisoryCommand(
+            server_handle=server_handle,
+            item_handle=item_handle,
+        ),
+    )
+)
+
+await session.write(server_handle, item_handle, value, user_id=user_id)
+```
+
+The CLI exposes the same command as `advise-supervisory`, and `write` /
+`write2` take `--user-id`.
+
+### Array writes replace the whole array
+
+A write to an array attribute **replaces the entire array**; it is not an
+element-wise patch. To change a subset of elements, send the full array with
+the unchanged elements included. For example, to change 2 elements of a
+20-element array, build the `MxValue` from all 20 values (the 18 unchanged plus
+the 2 new ones). Sending only the 2 changed values overwrites the attribute
+with a 2-element array.
+
 ## Galaxy Repository Browse
 
 The `GalaxyRepositoryClient` wraps the read-only `GalaxyRepository` gRPC

clients/python/src/zb_mom_ww_mxgateway_cli/commands.py

@@ -277,6 +277,23 @@ def advise(**kwargs: Any) -> None:
     _run(_advise(**kwargs), output_json=kwargs["output_json"], secrets=_secrets(kwargs))
 
 
+@main.command("advise-supervisory")
+@gateway_options
+@click.option("--session-id", required=True, help="Gateway session id.")
+@click.option("--server-handle", required=True, type=int, help="MXAccess server handle.")
+@click.option("--item-handle", required=True, type=int, help="MXAccess item handle.")
+@click.option("--correlation-id", default="", help="Client correlation id.")
+@click.option("--json", "output_json", is_flag=True, help="Emit JSON output.")
+def advise_supervisory(**kwargs: Any) -> None:
+    """Invoke MXAccess AdviseSupervisory."""
+
+    _run(
+        _advise_supervisory(**kwargs),
+        output_json=kwargs["output_json"],
+        secrets=_secrets(kwargs),
+    )
+
+
 @main.command("subscribe-bulk")
 @gateway_options
 @click.option("--session-id", required=True, help="Gateway session id.")
@@ -725,6 +742,22 @@ async def _advise(**kwargs: Any) -> dict[str, Any]:
         return {"ok": True}
 
 
+async def _advise_supervisory(**kwargs: Any) -> dict[str, Any]:
+    async with await _connect(kwargs) as client:
+        session = _session(client, kwargs["session_id"])
+        await session.invoke(
+            pb.MxCommand(
+                kind=pb.MX_COMMAND_KIND_ADVISE_SUPERVISORY,
+                advise_supervisory=pb.AdviseSupervisoryCommand(
+                    server_handle=kwargs["server_handle"],
+                    item_handle=kwargs["item_handle"],
+                ),
+            ),
+            correlation_id=kwargs["correlation_id"],
+        )
+        return {"ok": True}
+
+
 async def _subscribe_bulk(**kwargs: Any) -> dict[str, Any]:
     async with await _connect(kwargs) as client:
         session = _session(client, kwargs["session_id"])