wcc+ww: //ww:module-reset boundary directive; package-less files keep module "" (#16 PREP-main)

Driver twins emit the line-comment directive only before package-less
files (peekpackage==nil); both lexers tokenize it (TK_MODRESET, appended
=87 so existing token values hold) and both parsers reset curmod — a
package-less file's decls get module "" instead of inheriting the last
bundled package (the sticky-curmod leak, task #11). Withdrawn
alternative: injecting 'package main' flips non-entry symbols
bare->main-prefixed (FFI-visible, broke 764). Codegen-neutral by proof:
bare symbols preserved, both stages emit byte-identical asm for a
directive-bearing combined. Transitional until strict-package rejects
package-less files outright. Includes 737 bad-deep pin for the
PREP-peek >2048 edge + 904/toktest rows for the new token.

cmd/wcc/tok.c

@@ -103,6 +103,7 @@ tokname(Tkind k)
 	case TK_UNDER:		return "_";
 	case TK_ENUM:		return "enum";
 	case TK_MODULE:		return "package";
+	case TK_MODRESET:	return "//ww:module-reset";
 
 	case TK_LPAREN:		return "(";
 	case TK_RPAREN:		return ")";