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/components_updater_job.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env bash
 set -eo pipefail
 
 ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
@@ -138,7 +138,11 @@ tmp_file_line="$(grep -n '^function make_tmp_file' "$ACTION_UC" | cut -d: -f1)"
 [ -n "$init_line" ] && [ -n "$tmp_file_line" ] && [ "$init_line" -lt "$tmp_file_line" ] ||
   fail "components/action.uc must declare init_tmp_dir before make_tmp_file for OpenWrt ucode"
 
-sed -n '26,64p' "$ACTION_UC" >"$WORK_DIR/action-command-success.uc"
+awk '
+/^function as_string\(value\)/ { capture = 1 }
+/^function command_output\(command\)/ { capture = 0 }
+capture { print }
+' "$ACTION_UC" >"$WORK_DIR/action-command-success.uc"
 cat >>"$WORK_DIR/action-command-success.uc" <<'UCODE'
 let output_path = ARGV[0] || "";
 if (output_path == "" ||