refactor: clean install backup — dbi.config and prod.keys only

- Backup/restore DBI settings file instead of whole DBI folder
- Remove Tinfoil folder backup/restore
- Adjust deletion_lists_clean.h comments; UI strings in install_clean.c

Made-with: Cursor

source/deletion_lists_clean.h

@@ -2,8 +2,7 @@
  * OmniNX Installer - Deletion Lists for Clean Install Mode
  * Deletion policy aligned with NiklasCFW pack clean install (TegraExplorer script):
  * full sd:/atmosphere, bootloader/config subsets, sd:/switch, root + misc, then
- * post-restore paths (e.g. tinfoil db). Backup/restore of DBI, Tinfoil, prod.keys
- * is implemented in backup.c, not here.
+ * post-restore paths (e.g. tinfoil db). DBI/prod.keys backup is in backup.c.
  */
 
 #pragma once
@@ -114,7 +113,7 @@ static const char* clean_misc_files_to_delete[] = {
     NULL
 };
 
-// After DBI/Tinfoil/prod.keys restore (NiklasCFW: deldir("sd:/switch/tinfoil/db"))
+// After DBI/prod.keys restore (NiklasCFW: deldir("sd:/switch/tinfoil/db"))
 static const char* clean_post_restore_dirs_to_delete[] = {
     "sd:/switch/tinfoil/db",
     NULL