chore(sonar)!: cascade CA1822 through Markdown dialect wrappers

Commit 5202d93 made the SqlServer-namespaced Markdown generator methods
static, which left the LinqToSql / PostgreSql / Snowflake wrapper
classes' instance methods delegating to nothing but a static call.
SonarQube re-flagged those 10 wrapper methods as CA1822 on the next
scan.

This sweep:

- Makes all 10 wrapper instance methods `static` (`dotnet format` driven).
- Makes `Markdown.LinqToSql.QueryBreakdownGenerator.GenerateCombinedDiagram`
  static preemptively — it composes two static helpers and would otherwise
  be the next-iteration cascade flag.
- Removes the now-dead `_baseGenerator` field and its initializing
  constructor from all six dialect wrappers (LinqToSql / PostgreSql /
  Snowflake × QueryBreakdownGenerator + SqlStatementGenerator). The
  classes keep their implicit parameterless constructor so `new
  Snowflake.QueryBreakdownGenerator()` still compiles.
- Updates the one test call site (`GenerateCombinedDiagram`) the fixer
  didn't catch to use type-name form.

BREAKING CHANGE: External NuGet consumers calling
`instance.Generate*Diagram(...)` on `Markdown.LinqToSql.*`,
`Markdown.PostgreSql.*`, or `Markdown.Snowflake.*` generators must
switch to type-name form, e.g. `Markdown.Snowflake.SqlStatementGenerator.GenerateSequenceDiagram(...)`.
The class types and parameterless constructors remain — only the call
syntax for these methods changes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Strata.SqlTools.Markdown/Snowflake/SqlStatementGenerator.cs

@@ -8,23 +8,13 @@ namespace Strata.SqlTools.Markdown.Snowflake;
 /// </summary>
 public class SqlStatementGenerator
 {
-    private readonly SqlServer.SqlStatementGenerator _baseGenerator;
-
-    /// <summary>
-    /// Initializes a new instance of the SqlStatementGenerator class.
-    /// </summary>
-    public SqlStatementGenerator()
-    {
-        _baseGenerator = new SqlServer.SqlStatementGenerator();
-    }
-
     /// <summary>
     /// Generates a Mermaid sequence diagram showing Snowflake SQL statement execution flow.
     /// </summary>
     /// <param name="sqlBreakdown">The Snowflake SQL breakdown object.</param>
     /// <param name="title">Optional title for the diagram.</param>
     /// <returns>A string containing the Mermaid sequence diagram markdown.</returns>
-    public string GenerateSequenceDiagram(SqlBreakdownBase sqlBreakdown, string? title = null)
+    public static string GenerateSequenceDiagram(SqlBreakdownBase sqlBreakdown, string? title = null)
     {
         return SqlServer.SqlStatementGenerator.GenerateSequenceDiagram(sqlBreakdown, title);
     }
@@ -35,7 +25,7 @@ public class SqlStatementGenerator
     /// <param name="tables">Collection of table names to include in the diagram.</param>
     /// <param name="title">Optional title for the diagram.</param>
     /// <returns>A string containing the Mermaid ER diagram markdown.</returns>
-    public string GenerateEntityRelationshipDiagram(IEnumerable<string> tables, string? title = null)
+    public static string GenerateEntityRelationshipDiagram(IEnumerable<string> tables, string? title = null)
     {
         return SqlServer.SqlStatementGenerator.GenerateEntityRelationshipDiagram(tables, title);
     }