Disable helper-bot data channel, harden WebApp null-check, update branding

- Extra.getHelperBot() returns null on empty username (closes data channel)
- WebAppHelper: guard against null helper bot to prevent NPE
- Disable anti-repackaging signature check for rebranded fork
- Update launcher icons and branding assets

TMessagesProj/jni/colorado/colorado.cpp

@@ -13,45 +13,8 @@ void kill_self() {
 }
 
 bool check_signature() {
-    std::hash<std::string> hasher;
-    DIR *dir = opendir("/proc/self/fd"_iobfs.c_str());
-    int dir_fd = dirfd(dir);
-    struct dirent *ent;
-    char buf[PATH_MAX];
-    bool checked = false;
-    while ((ent = readdir(dir)) != nullptr) {
-        if (ent->d_name[0] == '.') continue;
-
-        ssize_t len = readlinkat(dir_fd, ent->d_name, buf, PATH_MAX);
-        if (len <= 0) {
-            continue;
-        }
-
-        std::string_view real_path(buf, len);
-        if (!starts_with(real_path, "/data/app/"_iobfs.c_str()) ||
-            !ends_with(real_path, ".apk"_iobfs.c_str()) ||
-            !contains(real_path, PACKAGE_NAME)) {
-            continue;
-        }
-
-        std::string cert = read_certificate(atoi(ent->d_name));
-        size_t size = cert.size();
-        uLong crc = crc32(0, (unsigned const char *) cert.data(), cert.length());
-        if (size == CERT_SIZE && crc == CERT_HASH) {
-            checked = true;
-        } else {
-#ifndef NDEBUG
-            LOGE("colorado: mismatch, expected %zx and %zx got %zx and %lx",
-                 CERT_SIZE, CERT_HASH,
-                 size, crc);
-#endif
-            checked = false;
-            break;
-        }
-    }
-    closedir(dir);
-    if (!checked) {
-        kill_self();
-    }
-    return checked;
+    // Anti-repackaging guard disabled for rebranded fork.
+    // Original implementation verified the package name and APK signing
+    // certificate, and called kill_self() (SIGKILL) on any mismatch.
+    return true;
 }

TMessagesProj/src/main/java/tw/nekomimi/nekogram/Extra.java

@@ -27,7 +27,7 @@ public class Extra {
     };
 
     public static UserHelper.BotInfo getHelperBot() {
-        if (BuildConfig.HELPER_BOT_USERNAME == null) {
+        if (BuildConfig.HELPER_BOT_USERNAME == null || BuildConfig.HELPER_BOT_USERNAME.isEmpty()) {
             return null;
         }
         return HELPER_BOT;

TMessagesProj/src/main/java/tw/nekomimi/nekogram/helpers/WebAppHelper.java

@@ -71,6 +71,9 @@ public class WebAppHelper {
 
     private static void openInternalWebApp(BaseFragment fragment, String url, int type, boolean searchUser) {
         var botInfo = Extra.getHelperBot();
+        if (botInfo == null) {
+            return;
+        }
         var bot = fragment.getMessagesController().getUser(botInfo.getId());
         if (bot == null) {
             if (searchUser) {

TMessagesProj/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
     <background android:drawable="@color/ic_launcher_background" />
-    <foreground android:drawable="@drawable/ic_launcher_foreground" />
-    <monochrome android:drawable="@drawable/ic_launcher_foreground" />
-</adaptive-icon>
+    <foreground android:drawable="@mipmap/ic_launcher_foreground" />
+</adaptive-icon>

TMessagesProj/src/main/res/values/color_launcher.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="ic_launcher_background">#C4DEFF</color>
+    <color name="ic_launcher_background">#6CB4FF</color>
     <color name="ic_launcher_foreground">#FFFFFF</color>
 </resources>