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/Configurations/TemplateConfiguration.cs

@@ -6,6 +6,8 @@ namespace ScadaLink.ConfigurationDatabase.Configurations;
 
 public class TemplateConfiguration : IEntityTypeConfiguration<Template>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="Template"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<Template> builder)
     {
         builder.HasKey(t => t.Id);
@@ -61,6 +63,8 @@ public class TemplateConfiguration : IEntityTypeConfiguration<Template>
 
 public class TemplateAttributeConfiguration : IEntityTypeConfiguration<TemplateAttribute>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="TemplateAttribute"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<TemplateAttribute> builder)
     {
         builder.HasKey(a => a.Id);
@@ -88,6 +92,8 @@ public class TemplateAttributeConfiguration : IEntityTypeConfiguration<TemplateA
 
 public class TemplateAlarmConfiguration : IEntityTypeConfiguration<TemplateAlarm>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="TemplateAlarm"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<TemplateAlarm> builder)
     {
         builder.HasKey(a => a.Id);
@@ -112,6 +118,8 @@ public class TemplateAlarmConfiguration : IEntityTypeConfiguration<TemplateAlarm
 
 public class TemplateScriptConfiguration : IEntityTypeConfiguration<TemplateScript>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="TemplateScript"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<TemplateScript> builder)
     {
         builder.HasKey(s => s.Id);
@@ -141,6 +149,8 @@ public class TemplateScriptConfiguration : IEntityTypeConfiguration<TemplateScri
 
 public class TemplateCompositionConfiguration : IEntityTypeConfiguration<TemplateComposition>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="TemplateComposition"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<TemplateComposition> builder)
     {
         builder.HasKey(c => c.Id);
@@ -161,6 +171,8 @@ public class TemplateCompositionConfiguration : IEntityTypeConfiguration<Templat
 
 public class TemplateFolderConfiguration : IEntityTypeConfiguration<TemplateFolder>
 {
+    /// <summary>Configures the EF Core mapping for <see cref="TemplateFolder"/>.</summary>
+    /// <param name="builder">The entity type builder.</param>
     public void Configure(EntityTypeBuilder<TemplateFolder> builder)
     {
         builder.HasKey(f => f.Id);