fix(mtconnect): redact the Agent URI everywhere it is shown (R06:T-8)

The driver logged and surfaced the raw AgentUri (which may carry user:pass@) as
HostName (the /hosts key), in ~20 log lines and in exception messages that reach
DriverHealth.LastError, and the client's request-URI messages (timeouts, stream
end, not-a-stream, framing) embedded it too - while the Test-Connect probe
deliberately redacted it. New MTConnectUriRedaction (user-info, and for the
configured string its query, removed; a clean URI is unchanged so host keys do
not move); the driver computes its display form once per options document.

Refs #743

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

docs/drivers/MTConnect.md

@@ -156,7 +156,7 @@ Read off `MTConnectDriverOptions` / `MTConnectDriverConfigDto`
 
 | Key | Default | Notes |
 |---|---|---|
-| `AgentUri` | — (required) | Agent base URI; the driver appends `/probe`, `/current`, `/sample` |
+| `AgentUri` | — (required) | Agent base URI; the driver appends `/probe`, `/current`, `/sample`. Any `user:pass@` (and query) is **redacted** from `HostName` (the `/hosts` key), every log line and every exception / health message (review 2026-10-21 T-8); a URI without credentials is shown unchanged |
 | `DeviceName` | `null` | **Double duty.** (1) Scopes requests to `{AgentUri}/{DeviceName}/...`; `null` = whole Agent. (2) The write path's fallback device — the device a write is addressed to when the probe model does not say which device declared the DataItem (see [Write-back](#write-back--observation-injection-off-by-default)) |
 | `RequestTimeoutMs` | `5000` | Per-call deadline for `/probe` and `/current` |
 | `SampleIntervalMs` | `1000` | The Agent's `/sample?interval=` query param |