test(formatter): add metadata boundary corpus guards

test/corpus/watcom/metadata-inline-header-boundary.expected.sql

@@ -0,0 +1,15 @@
+CREATE PROCEDURE "fct"."metadata_boundary"()
+-- METADATA
+-- Description : Keeps CREATE PROCEDURE text in metadata comments untouched.
+-- Version     : 1.0
+-- Author      : Test Author
+-- Updated By  : Test Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Initial creation mentions SELECT FROM WHERE - 2026-06-10 Test Author
+-- METADATA END
+BEGIN
+  SELECT 'CREATE PROCEDURE dbo.fake_object() should stay literal' AS description;
+  -- CREATE FUNCTION dbo.fake_comment() should stay comment text
+END;

test/corpus/watcom/metadata-inline-header-boundary.input.sql

@@ -0,0 +1,15 @@
+create procedure "fct"."metadata_boundary"()
+-- METADATA
+-- Description : Keeps CREATE PROCEDURE text in metadata comments untouched.
+-- Version     : 1.0
+-- Author      : Test Author
+-- Updated By  : Test Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Initial creation mentions SELECT FROM WHERE - 2026-06-10 Test Author
+-- METADATA END
+begin
+select 'CREATE PROCEDURE dbo.fake_object() should stay literal' as description;
+-- CREATE FUNCTION dbo.fake_comment() should stay comment text
+end;

test/corpus/watcom/metadata-multiple-headers-boundary.expected.sql

@@ -0,0 +1,30 @@
+-- CREATE PROCEDURE dbo.comment_decoy() should not affect metadata boundaries
+CREATE PROCEDURE dbo.first_metadata_boundary()
+-- METADATA
+-- Description : First object header mentions CREATE FUNCTION as prose.
+-- Version     : 1.0
+-- Author      : First Author
+-- Updated By  : First Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Created before the second metadata header - 2026-06-10 First Author
+-- METADATA END
+BEGIN
+  SELECT 1;
+END;
+
+CREATE FUNCTION dbo.second_metadata_boundary() RETURNS integer
+-- METADATA
+-- Description : Second object header mentions CREATE TRIGGER as prose.
+-- Version     : 1.0
+-- Author      : Second Author
+-- Updated By  : Second Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Created after the first metadata header - 2026-06-10 Second Author
+-- METADATA END
+BEGIN
+  RETURN 2;
+END;

test/corpus/watcom/metadata-multiple-headers-boundary.input.sql

@@ -0,0 +1,30 @@
+-- CREATE PROCEDURE dbo.comment_decoy() should not affect metadata boundaries
+create procedure dbo.first_metadata_boundary()
+-- METADATA
+-- Description : First object header mentions CREATE FUNCTION as prose.
+-- Version     : 1.0
+-- Author      : First Author
+-- Updated By  : First Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Created before the second metadata header - 2026-06-10 First Author
+-- METADATA END
+begin
+select 1;
+end;
+
+create function dbo.second_metadata_boundary() returns integer
+-- METADATA
+-- Description : Second object header mentions CREATE TRIGGER as prose.
+-- Version     : 1.0
+-- Author      : Second Author
+-- Updated By  : Second Author
+-- Created     : 2026-06-10
+-- Updated     : 2026-06-10
+-- History     :
+--   v1.0: Created after the first metadata header - 2026-06-10 Second Author
+-- METADATA END
+begin
+return 2;
+end;