fix: correct using paths in selfhost VM apps for compatibility

- Update mini_vm_core.nyash: fix using paths to point to correct locations
  - selfhost.vm.json -> selfhost.vm.boxes.json_cur
  - selfhost.vm.scan -> selfhost.common.mini_vm_scan
  - selfhost.vm.binop -> selfhost.common.mini_vm_binop
  - selfhost.vm.compare -> selfhost.common.mini_vm_compare
- Update smoke test apps to use correct mini_vm_core path
- Addresses using system parser errors at line 1885 and brace delta issues

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/selfhost/vm/boxes/mini_vm_core.nyash

@@ -1,8 +1,8 @@
-using selfhost.vm.json as MiniJson
-using selfhost.vm.scan as MiniVmScan
-using selfhost.vm.binop as MiniVmBinOp
-using selfhost.vm.compare as MiniVmCompare
-using selfhost.vm.prints as MiniVmPrints
+using selfhost.vm.boxes.json_cur as MiniJson
+using selfhost.common.mini_vm_scan as MiniVmScan
+using selfhost.common.mini_vm_binop as MiniVmBinOp
+using selfhost.common.mini_vm_compare as MiniVmCompare
+using selfhost.vm.boxes.mini_vm_prints as MiniVmPrints
 
 static box MiniVm {
   _is_digit(ch) {
@@ -745,5 +745,3 @@ static box MiniVm {
     return out
   }
 }
-
-// Program entry: prefer argv[0] JSON, fallback to embedded sample

apps/selfhost/vm/collect_empty_args_using_smoke.nyash

@@ -1,4 +1,4 @@
-using selfhost.vm.core as MiniVm
+using selfhost.vm.boxes.mini_vm_core as MiniVm
 
 static box Main {
   main(args) {

apps/selfhost/vm/collect_mixed_using_smoke.nyash

@@ -1,5 +1,5 @@
-using selfhost.vm.core as MiniVm
-using selfhost.vm.prints as MiniVmPrints
+using selfhost.vm.boxes.mini_vm_core as MiniVm
+using selfhost.vm.boxes.mini_vm_prints as MiniVmPrints
 
 static box Main {
   main(args) {