chore(deploy): drop the AWS golden-image build stack

Remove the release-driven Packer AMI/qcow2 pipeline and everything that existed only to feed it: the image.yml workflow, deploy/packer, deploy/lightsail, deploy/firstboot, the AWS Marketplace checklist, and the first-boot smoke test/job.

Keep the cloud-agnostic unattended-install path (cloud-init + install.sh non-interactive) and the Hetzner notes, which never depended on the workflow. Hetzner's snapshot path is dropped too since it relied on firstboot to avoid admin/admin on clones; cloud-init regenerates per-instance credentials on its own.

Update deploy/README, the cloud-init and Hetzner docs, the root README plus its six translations, and .gitattributes to match.

deploy/test/smoke-firstboot.sh

@@ -1,86 +0,0 @@
-#!/usr/bin/env bash
-#
-# smoke-firstboot.sh — verify the first-boot per-instance credential script.
-#
-# Installs the released x-ui binary into a container WITHOUT a database, runs
-# x-ui-firstboot.sh, and asserts:
-#   * fresh random credentials are generated (no admin/admin)
-#   * /etc/x-ui/credentials.txt (600) and /etc/motd are written
-#   * the sentinel is created and a second run is a no-op (creds unchanged)
-#
-# Requires Docker and network access. Usage: bash deploy/test/smoke-firstboot.sh
-set -euo pipefail
-
-REPO_ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
-IMAGE="${SMOKE_IMAGE:-ubuntu:24.04}"
-
-if ! command -v docker > /dev/null 2>&1; then
-    echo "ERROR: docker is required for this smoke test." >&2
-    exit 1
-fi
-
-echo "== first-boot credential smoke test (image: $IMAGE) =="
-
-docker run --rm \
-    -v "${REPO_ROOT}/deploy/firstboot/x-ui-firstboot.sh:/root/x-ui-firstboot.sh:ro" \
-    -e DEBIAN_FRONTEND=noninteractive \
-    "$IMAGE" bash -euo pipefail -c '
-        apt-get update -qq
-        apt-get install -y -qq curl tar openssl ca-certificates jq > /dev/null
-
-        echo "--- installing released x-ui binary (no DB, no systemd) ---"
-        REPO=MHSanaei/3x-ui
-        ARCH=$(dpkg --print-architecture)   # amd64 | arm64
-        echo "container arch: $ARCH"
-        VER=$(curl --fail --location --silent --show-error \
-            --retry 5 --retry-all-errors --retry-delay 3 \
-            --connect-timeout 15 --max-time 60 \
-            "https://api.github.com/repos/${REPO}/releases/latest" | jq -r .tag_name)
-        [ -n "$VER" ] && [ "$VER" != "null" ] || { echo "FAIL: cannot resolve version"; exit 1; }
-        tmp=$(mktemp -d)
-        # 504s and other transient GitHub/CDN hiccups are retried; a real HTTP
-        # failure (e.g. missing arch asset) still aborts after the retries.
-        if ! curl -4 --fail --location --silent --show-error \
-            --retry 5 --retry-all-errors --retry-delay 3 \
-            --connect-timeout 15 --max-time 300 \
-            -o "${tmp}/x.tar.gz" \
-            "https://github.com/${REPO}/releases/download/${VER}/x-ui-linux-${ARCH}.tar.gz"; then
-            echo "FAIL: cannot download x-ui-linux-${ARCH}.tar.gz (${VER})" >&2; exit 1
-        fi
-        test -s "${tmp}/x.tar.gz" || { echo "FAIL: downloaded tarball is empty"; exit 1; }
-        tar -xzf "${tmp}/x.tar.gz" -C /usr/local/
-        chmod +x /usr/local/x-ui/x-ui
-        install -m 755 /root/x-ui-firstboot.sh /usr/local/x-ui/x-ui-firstboot.sh
-
-        # Guarantee a clean slate (the image must never ship a DB).
-        rm -f /etc/x-ui/x-ui.db /etc/x-ui/.firstboot-done
-
-        echo "--- run 1: generate per-instance credentials ---"
-        /usr/local/x-ui/x-ui-firstboot.sh
-
-        test -f /etc/x-ui/.firstboot-done || { echo "FAIL: sentinel not created"; exit 1; }
-        test -f /etc/x-ui/credentials.txt || { echo "FAIL: credentials.txt missing"; exit 1; }
-        perms=$(stat -c %a /etc/x-ui/credentials.txt)
-        [ "$perms" = "600" ] || { echo "FAIL: credentials.txt perms=$perms (want 600)"; exit 1; }
-        grep -q "3x-ui" /etc/motd || { echo "FAIL: motd not written"; exit 1; }
-
-        # shellcheck disable=SC1090
-        . /etc/x-ui/credentials.txt
-        [ -n "${XUI_USERNAME:-}" ] && [ "$XUI_USERNAME" != "admin" ] \
-            || { echo "FAIL: username missing or still admin"; exit 1; }
-        first_user="$XUI_USERNAME"
-
-        /usr/local/x-ui/x-ui setting -show | grep -q "hasDefaultCredential: false" \
-            || { echo "FAIL: hasDefaultCredential is not false"; exit 1; }
-
-        echo "--- run 2: must be a no-op (sentinel honored) ---"
-        /usr/local/x-ui/x-ui-firstboot.sh
-        # shellcheck disable=SC1090
-        . /etc/x-ui/credentials.txt
-        [ "$XUI_USERNAME" = "$first_user" ] \
-            || { echo "FAIL: credentials changed on re-run"; exit 1; }
-
-        echo "SMOKE_PASS: firstboot user=$first_user (stable across re-run)"
-    '
-
-echo "== first-boot smoke test PASSED =="