docs: add XML doc comments across src + Sister Projects section in CLAUDE.md

Bulk CommentChecker pass: fills in <param>/<inheritdoc> tags on public
APIs across all 23 src/ projects so the doc-coverage gate is green. Also
adds a Sister Projects section to CLAUDE.md pointing at the MxAccess
Gateway and OtOpcUa sibling repos, and gitignores local credential
captures (*login*.txt) and the wonder-app-vd03 deploy/ artifacts.

src/ScadaLink.CLI/CliConfig.cs

@@ -2,9 +2,14 @@ using System.Text.Json;
 
 namespace ScadaLink.CLI;
 
+/// <summary>
+/// Resolved CLI configuration combining config file values, environment variable overrides, and per-invocation credentials.
+/// </summary>
 public class CliConfig
 {
+    /// <summary>Base URL of the ScadaLink Management API (e.g. http://localhost:9000).</summary>
     public string? ManagementUrl { get; set; }
+    /// <summary>Default output format for CLI commands; defaults to "json".</summary>
     public string DefaultFormat { get; set; } = "json";
 
     /// <summary>
@@ -21,6 +26,10 @@ public class CliConfig
     /// </summary>
     public string? Password { get; set; }
 
+    /// <summary>
+    /// Loads CLI configuration by merging the config file, environment variables, and credential env vars.
+    /// </summary>
+    /// <returns>A populated <see cref="CliConfig"/> instance.</returns>
     public static CliConfig Load()
     {
         var config = new CliConfig();
@@ -66,7 +75,9 @@ public class CliConfig
 
     private class CliConfigFile
     {
+        /// <summary>Management API URL from the config file.</summary>
         public string? ManagementUrl { get; set; }
+        /// <summary>Default output format from the config file.</summary>
         public string? DefaultFormat { get; set; }
     }
 }