fix: align verify and pack validation, pipeline 100% consistent

generate_pack.py now applies emulator-level validation (crc32, sha1,
adler32) matching verify.py behavior. existence mode: validation is
informational (file present = OK). md5 mode: validation downgrades
to UNTESTED. clone resolution moved to common.py resolve_local_file.
all 6 platforms pass consistency check.

database.json

@@ -1,5 +1,5 @@
 {
-  "generated_at": "2026-03-24T20:51:56Z",
+  "generated_at": "2026-03-24T21:16:05Z",
   "total_files": 6733,
   "total_size": 5288644732,
   "files": {
@@ -24394,7 +24394,7 @@
       "adler32": "9147003d"
     },
     "db1031585968cfc6ec2ecda5c9a5a52f61444a3b": {
-      "path": "bios/Atari/400-800/.variants/ATARIOSB.ROM.db103158",
+      "path": "bios/Atari/400-800/.variants/ATARIOSB.ROM.0e86d61d",
       "name": "ATARIOSB.ROM",
       "size": 10240,
       "sha1": "db1031585968cfc6ec2ecda5c9a5a52f61444a3b",
@@ -105197,7 +105197,7 @@
       ".variants/1540OS3.V0": [
         "454fdd9005c43142f827e1e506bf75fda0fe2a65"
       ],
-      ".variants/ATARIOSB.ROM.db103158": [
+      ".variants/ATARIOSB.ROM.0e86d61d": [
         "db1031585968cfc6ec2ecda5c9a5a52f61444a3b"
       ],
       "tos/emutos.img": [