Merge review R3 fixes: per-page interactive ErrorBoundary, DisposeBridge cancels on timeout, CSV commit refreshes after close, SecurityMode=None documented, browsePageDelayMs omit-by-default

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

docs/Client.CLI.md

@@ -41,6 +41,12 @@ All commands accept these options:
 | `-F` / `--failover-urls` | Comma-separated failover endpoint URLs for redundancy |
 | `--verbose` | Enable debug-level Serilog console logging (default: warning) |
 
+**`--security none` does not fall back.** Endpoint selection picks the server's `None`-policy endpoint and
+fails with an `InvalidOperationException` naming the endpoints the server does offer when it has none. The
+older stack helper silently fell back to the first endpoint (often a secured one), so a command that
+defaulted to `none` against a secured-only server used to connect and now errors. Pass `-S sign`,
+`-S encrypt` or `-S signandencrypt` to talk to such a server.
+
 ### Authentication
 
 When `-U` and `-P` are provided, the shared service passes a `UserIdentity(username, password)` to the OPC UA session. Without credentials, anonymous identity is used.

docs/Client.UI.md

@@ -57,7 +57,7 @@ The top bar provides the endpoint URL, Connect, and Disconnect buttons. The **Co
 |---------|-------------|
 | Endpoint URL | OPC UA server endpoint (e.g., `opc.tcp://localhost:4840/OtOpcUa`) |
 | Username / Password | Credentials for `UserName` token authentication |
-| Security Mode | Transport security: None, Sign, SignAndEncrypt |
+| Security Mode | Transport security: None, Sign, SignAndEncrypt. `None` requires the server to offer a `None` endpoint — there is no fallback to a secured one; connecting fails naming the endpoints offered |
 | Failover URLs | Comma-separated backup endpoints for redundancy failover |
 | Session Timeout | Session timeout in seconds (1–3600, default 60) |
 | Certificate Store Path | Path to the client certificate store (folder chooser) |