fix(auth.apikeys): stamp schema version 2 to match donor gateway DBs; bump 0.1.2

The store was extracted from MxAccessGateway, whose deployed gateway-auth.db
is at schema_version=2. The library capped at 1 and threw on a newer on-disk
version -> gateway would fail to boot. Final schema is byte-identical since v1;
stamp 2 so existing deployed DBs interoperate (no key re-issuance). +2 tests.

ZB.MOM.WW.Auth/tests/ZB.MOM.WW.Auth.ApiKeys.Tests/SqliteMigratorTests.cs

@@ -34,6 +34,27 @@ public sealed class SqliteMigratorTests : IDisposable
         Assert.Equal(1, await CountSchemaVersionRowsAsync());
     }
 
+    [Fact]
+    public void CurrentVersion_Is2_ToMatchDonorGatewayDeployedSchema() =>
+        // The store was extracted from MxAccessGateway, whose deployed gateway-auth.db is
+        // stamped version 2. The library must stamp 2 (not reset to 1) so it does not refuse
+        // those existing databases on first boot. Locking this invariant.
+        Assert.Equal(2, SqliteAuthSchema.CurrentVersion);
+
+    [Fact]
+    public async Task MigrateAsync_AgainstExistingVersion2Db_DoesNotThrow_AndStaysAt2()
+    {
+        // The deployed-gateway scenario: a database already provisioned at version 2.
+        var migrator = new SqliteAuthStoreMigrator(Factory);
+        await migrator.MigrateAsync(CancellationToken.None);
+        await SetVersionAsync(2);
+
+        await migrator.MigrateAsync(CancellationToken.None); // must not throw
+
+        Assert.Equal(2, await ReadVersionAsync());
+        Assert.True(await TableExistsAsync(SqliteAuthSchema.ApiKeysTable));
+    }
+
     [Fact]
     public async Task MigrateAsync_FutureSchemaVersion_Throws()
     {