docs: update about new checksum measure

with v6.5.15+, the checksum is enhanced...

Signed-off-by: Cuynu <cuynu@proton.me>

docs/checksum_newapp.md

@@ -0,0 +1,43 @@
+
+
+# MBBank v6.5.15+  checksum list
+
+in first day of v6.5.15+ released, there is no such checksum, it still the same as before, only until 4 days since release, there is toggle in backend that enable the check, remain unaffected for older base
+
+same as v6.4.63+, in first day nothing happens, no checksum, but after 9 days, checksum appears.
+
+if one of these is modified (even one bit) will trigger checksum fail that refuse to accept login from
+
+all of this is both app & server side, server side ask for checksum, the client get sha256 hash and send to server side `getSHFiles` and if something mismatch, the server side will refuse to login and return GW934 as response to app
+
+```shell
+# outside assets (v6.5.15+)
+mb.apk/AndroidManifest.xml
+mb.apk/lib/arm64-v8a/*.so # previously is libapp / zshield & zdefend libs only since v6.4.63+
+mb.apk/lib/armeabi-v7a/*.so # previously is libapp / zshield & zdefend libs only since v6.4.63+
+mb.apk/classes*.dex # since v6.4.63+
+
+# in assets
+# zimperium (v6.5.15+)
+mb.apk/assets/zimperium_local_model_randomized_filename* 
+mb.apk/assets/zimperium_encrypted_dex_folder/*.odex
+mb.apk/assets/*.szip # zshield encrypted files
+
+# vkey vtap (v6.5.15+)
+mb.apk/assets/firmware # vkey vtap fw
+mb.apk/assets/profile # vkey vtap profile
+mb.apk/assets/signature # vtap vkey signature
+mb.apk/version.json # vtap vkey vos info
+mb.apk/voscodesign.vky
+mb.apk/vkeylicensepack
+
+# singalarity ekyc files (v6.5.15+)
+mb.apk/assets/sgprofile
+mb.apk/assets/smart_ekyc_finall.zip
+mb.apk/assets/media_init_data
+
+# flutter assets (v6.5.15+)
+mb.apk/assets/flutter_assets/assets/fonts/*
+mb.apk/assets/flutter_assets/fonts/*
+mb.apk/assets/flutter_assets/FontManifest.json
+```