Merge branch 'temp-upstream-rebrand' into main

Resolves merge conflicts:
- install.sh, build.sh, .github/workflows/build.yml: Reverted to Dushnilin's versions to avoid installing SourceForge mirrors.
- fe-app-tachyon: Resolved type, formatting and copyOutbound conflicts, keeping both Dushnilin's custom features and ushan0v's frontend performance optimizations.
- backend: Kept Dushnilin's ucode refactorings, Telegram bot integration, and release repository URL (Dushnilin/tachyon) while merging updates.uc cache format v8 & persistent cache format v7.
- tests: Merged tests from both branches, preserving ucode -L wrappers for local test execution.

tests/package_contract.sh

@@ -46,6 +46,18 @@ require_file "$TACHYON_CONFIG"
 require_file "$BUILD_SCRIPT"
 require_file "$TACHYON_LIB"
 
+for conflict in https-dns-proxy nextdns luci-app-passwall luci-app-passwall2; do
+  grep -E 'CONFLICTS:=' "$TACHYON_MAKEFILE" | grep -Fq "$conflict" ||
+    fail "tachyon/Makefile conflicts are missing $conflict"
+  grep -E '^BACKEND_CONFLICTS_IPK=' "$BUILD_SCRIPT" | grep -Fq "$conflict" ||
+    fail "manual IPK conflicts are missing $conflict"
+  grep -E '^BACKEND_DEPENDS_APK=' "$BUILD_SCRIPT" | grep -Fq "!$conflict" ||
+    fail "manual APK conflicts are missing $conflict"
+done
+
+if grep -Fq 'coreutils-sort' "$TACHYON_MAKEFILE" "$BUILD_SCRIPT"; then
+  fail "unused coreutils-sort runtime dependency must not be packaged"
+fi
 grep -Fq "must use x.y.z format" "$TACHYON_MAKEFILE" ||
   fail "tachyon/Makefile must enforce the three-part release version contract"
 grep -Fq 'APK_INTERNAL_VERSION="$RELEASE_VERSION"' "$BUILD_SCRIPT" ||