docs(r2-12): document 5 alarm operator CLI commands; fix StyleGuide product name; add minimal .editorconfig (07/U-3, 07/C-5)

- docs/Client.CLI.md: added ### ack / confirm / shelve / enable / disable sections
  (synopsis + options + example + expected output), each noting the AlarmAck LDAP-role
  gate and that --event-id comes from a prior `alarms` notification. Doc now covers all
  13 CLI commands (was 8). Overview operations list updated.
- StyleGuide.md: 'ScadaBridge' -> 'OtOpcUa' (header line 3) + the ScadaBridge:Timeout
  config-key example -> OpcUa:Timeout.
- .editorconfig (new, root): minimal code-style anchor; all C# analyzer rules at
  suggestion severity so nothing fails a TreatWarningsAsErrors build (verified: 808
  warnings unchanged from baseline, 0 errors).

StyleGuide.md

@@ -1,6 +1,6 @@
 # Documentation Style Guide
 
-This guide defines writing conventions and formatting rules for all ScadaBridge documentation.
+This guide defines writing conventions and formatting rules for all OtOpcUa documentation.
 
 ## Tone and Voice
 
@@ -144,7 +144,7 @@ Use backticks for:
 - Class names: `ScadaGatewayActor`
 - Method names: `HandleMessage()`
 - File names: `appsettings.json`
-- Configuration keys: `ScadaBridge:Timeout`
+- Configuration keys: `OpcUa:Timeout`
 - Command-line commands: `dotnet build`
 
 ### Links