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.ConfigurationDatabase/Maintenance/AuditLogPartitionMaintenance.cs

@@ -54,6 +54,9 @@ public sealed class AuditLogPartitionMaintenance : IPartitionMaintenance
     private readonly ScadaLinkDbContext _context;
     private readonly ILogger<AuditLogPartitionMaintenance> _logger;
 
+    /// <summary>Initializes the maintenance implementation with the database context and optional logger.</summary>
+    /// <param name="context">The EF Core database context used to execute partition-management SQL.</param>
+    /// <param name="logger">Optional logger; defaults to <see cref="NullLogger{T}"/> when null.</param>
     public AuditLogPartitionMaintenance(
         ScadaLinkDbContext context,
         ILogger<AuditLogPartitionMaintenance>? logger = null)