refactor(sql): dialect-owned parameter markers, bind names and command configuration

ISqlDialect gains ParameterMarker (the token in the SQL text), ParameterBindName
(the DbParameter.ParameterName) and ConfigureCommand (per-command provider setup,
where Oracle will set BindByName). SQL Server and the test SQLite dialect answer
"@"+name for both spellings and no-op the hook, so SQL Server behaviour is
byte-identical — every existing expected-SQL assertion passes untouched.

SqlGroupPlanner drops its hardcoded @k/@w consts and mints base names (k0..kN, w)
that the dialect spells; SqlQueryPlan carries the emitted markers AND the matching
bind names, so SqlPollReader keeps copying the plan's pairing rather than
re-deriving a provider convention (the two diverge on ODP.NET: ":k0" in the text,
bare "k0" on the parameter). SqlCatalogLoader and SqlBrowseSession bind
schema/table through the dialect, so their bind names cannot drift from the
markers in the dialect-owned catalog SQL. Every parameter-carrying command site
calls ConfigureCommand before its first parameter.

Controlled by a new test-only ColonMarkerDialect (":name" markers, bare bind
names) that really executes against the SQLite fixture. Each leg was falsified
against the pre-change behaviour: the planner emitted "@k0", the reader bound
":k0", and a hardcoded "@schema" in the loader failed catalog load outright.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.Tests/SqliteDialect.cs

@@ -42,6 +42,28 @@ public sealed class SqliteDialect : ISqlDialect
     /// <inheritdoc/>
     public DbProviderFactory Factory => SqliteFactory.Instance;
 
+    /// <summary>
+    ///     <c>@</c>-prefixed, matching SQL Server — SQLite accepts <c>@</c>, <c>:</c> and <c>$</c> equally, so
+    ///     this dialect deliberately keeps the <em>same</em> spelling as the production one. Divergent
+    ///     parameter naming is the job of <c>ColonMarkerDialect</c>, which is the control for it; if this
+    ///     dialect diverged too, a SQL-Server-shaped assumption would have nothing left holding it in place.
+    /// </summary>
+    /// <param name="baseName">The bare base name.</param>
+    /// <returns>The <c>@</c>-prefixed marker.</returns>
+    public string ParameterMarker(string baseName) => "@" + baseName;
+
+    /// <summary>Identical to the marker — <c>Microsoft.Data.Sqlite</c> matches on the prefixed name.</summary>
+    /// <param name="baseName">The bare base name.</param>
+    /// <returns>The <c>@</c>-prefixed bind name.</returns>
+    public string ParameterBindName(string baseName) => "@" + baseName;
+
+    /// <summary>No-op: <c>SqliteCommand</c> binds by name and needs no per-command setup.</summary>
+    /// <param name="command">The command to configure; untouched here.</param>
+    public void ConfigureCommand(DbCommand command)
+    {
+        // Intentionally empty: see the summary.
+    }
+
     /// <inheritdoc/>
     public string LivenessSql => "SELECT 1";