fix: module syntax — changed src_bux/*.bux from module X; to module X { ... }

src_bux/sema.bux

@@ -1,6 +1,6 @@
 // sema.bux — Semantic analysis (type checker, ported from sema.nim)
 // Validates types, resolves identifiers, checks function calls.
-module Sema;
+module Sema {
 
 // ---------------------------------------------------------------------------
 // Sema context
@@ -391,4 +391,4 @@ func Sema_Free(sema: *Sema) {
     bux_free(sema.scope as *void);
     bux_free(sema.diags as *void);
     bux_free(sema as *void);
-}
+}