chore: sync with microG unofficial installer

Signed-off-by: ale5000 <15793015+ale5000-git@users.noreply.github.com>

Author: ale5000-git

.all-contributorsrc

@@ -0,0 +1,17 @@
+{
+  "projectName": "google-sync-addon",
+  "projectOwner": "micro5k",
+  "repoType": "github",
+  "files": [
+    "docs/CONTRIBUTORS.md"
+  ],
+  "imageSize": 100,
+  "commit": true,
+  "commitConvention": "angular",
+  "commitType": "docs",
+  "contributorsPerLine": 6,
+  "contributorsSortAlphabetically": true,
+  "linkToUsage": true,
+  "skipCi": true,
+  "contributors": []
+}

docs/CONTRIBUTORS.md

@@ -0,0 +1,15 @@
+<!--
+    SPDX-FileCopyrightText: (c) 2026 ale5000
+    SPDX-License-Identifier: GPL-3.0-or-later
+    SPDX-FileType: DOCUMENTATION
+-->
+
+# Contributors ✨
+
+Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/en/emoji-key/)):
+
+<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
+<!-- ALL-CONTRIBUTORS-LIST:END -->
+
+This project follows the [all-contributors](https://allcontributors.org/) specification.
+Contributions of any kind are welcome!

zip-content/inc/common-functions.sh

@@ -34,8 +34,12 @@ export ASSOCIATED_LOOP_DEVICES=''
 export MOUNTED_APEX_CHILDREN=''
 readonly ROLLBACK_TEST='false'
 
-# Minimum size threshold (in bytes) for app rollback eligibility
-readonly APP_MIN_SIZE_FOR_ROLLING_BACK='102400' # 100 KiB
+# Default maximum API level used when an upper bound is not specified in configuration.
+# 999 is intentionally higher than any realistic Android API level and effectively means "no upper limit"
+readonly DEFAULT_MAX_API_LEVEL='999'
+
+# Minimum size threshold (in bytes) for app rollback eligibility => 100 KiB
+readonly APP_MIN_SIZE_FOR_ROLLING_BACK='102400'
 
 # shellcheck disable=SC3040,SC2015
 {
@@ -2317,10 +2321,10 @@ perform_installation()
   done
 
   if test "${API:?}" -lt 21; then
-    if test "${CPU64}" != false; then
+    if test "${CPU64:?}" != 'false'; then
       perform_secure_copy_to_device 'lib64'
     fi
-    if test "${CPU}" != false; then
+    if test "${CPU:?}" != 'false'; then
       perform_secure_copy_to_device 'lib'
     fi
   fi
@@ -2821,7 +2825,7 @@ setup_app()
   _output_dir=''
   _installed_file_list=''
 
-  if test "${API:?}" -ge "${_min_api:?}" && test "${API:?}" -le "${_max_api:-999}"; then
+  if test "${API:?}" -ge "${_min_api:?}" && test "${API:?}" -le "${_max_api:-"${DEFAULT_MAX_API_LEVEL:?}"}"; then
     if test "${_optional:?}" = 'true' && test "${LIVE_SETUP_ENABLED:?}" = 'true'; then
       choose "Do you want to install ${_vanity_name:?}?" '+) Yes' '-) No'
       if test "${?}" -eq 3; then _install='1'; else _install='0'; fi
@@ -2903,7 +2907,7 @@ setup_lib()
 
   _output_dir="${_dir:?}"
 
-  if test "${API:?}" -ge "${_min_api:?}" && test "${API:?}" -le "${_max_api:-999}"; then
+  if test "${API:?}" -ge "${_min_api:?}" && test "${API:?}" -le "${_max_api:-"${DEFAULT_MAX_API_LEVEL:?}"}"; then
     if test "${_optional:?}" = 'true' && test "${LIVE_SETUP_ENABLED:?}" = 'true'; then
       choose "Do you want to install ${_vanity_name:?}?" '+) Yes' '-) No'
       if test "${?}" -eq 3; then _install='1'; else _install='0'; fi
@@ -3420,6 +3424,7 @@ _timeout_compat()
 }
 
 _esc_keycode="$(printf '\033')"
+readonly _esc_keycode
 _choose_remapper()
 {
   local _key