add locales & fix multi_instance check

locales/en.json

@@ -13,6 +13,7 @@
     "app_already_installed": "{app} is already installed",
     "app_already_installed_cant_change_url": "This app is already installed. The URL cannot be changed just by this function. Check in `app changeurl` if it's available.",
     "app_already_up_to_date": "{app} is already up-to-date",
+    "app_arch_not_supported": "This app can only be installed on architectures {', '.join(required)} but your server architecture is {current}",
     "app_argument_choice_invalid": "Pick a valid value for argument '{name}': '{value}' is not among the available choices ({choices})",
     "app_argument_invalid": "Pick a valid value for the argument '{name}': {error}",
     "app_argument_password_no_default": "Error while parsing password argument '{name}': password argument can't have a default value for security reasons",
@@ -39,6 +40,8 @@
     "app_manifest_install_ask_password": "Choose an administration password for this app",
     "app_manifest_install_ask_path": "Choose the URL path (after the domain) where this app should be installed",
     "app_not_correctly_installed": "{app} seems to be incorrectly installed",
+    "app_not_enough_disk": "This app requires {required} free space.",
+    "app_not_enough_ram": "This app requires {required} RAM to install/upgrade but only {current} is available right now.",
     "app_not_installed": "Could not find {app} in the list of installed apps: {all_apps}",
     "app_not_properly_removed": "{app} has not been properly removed",
     "app_not_upgraded": "The app '{failed_app}' failed to upgrade, and as a consequence the following apps' upgrades have been cancelled: {apps}",
@@ -61,6 +64,7 @@
     "app_upgrade_several_apps": "The following apps will be upgraded: {apps}",
     "app_upgrade_some_app_failed": "Some apps could not be upgraded",
     "app_upgraded": "{app} upgraded",
+    "app_yunohost_version_not_supported": "This app requires YunoHost >= {required} but current installed version is {current}",
     "apps_already_up_to_date": "All apps are already up-to-date",
     "apps_catalog_failed_to_download": "Unable to download the {apps_catalog} app catalog: {error}",
     "apps_catalog_init_success": "App catalog system initialized!",
@@ -159,6 +163,7 @@
     "config_validate_url": "Should be a valid web URL",
     "config_version_not_supported": "Config panel versions '{version}' are not supported.",
     "confirm_app_install_danger": "DANGER! This app is known to be still experimental (if not explicitly not working)! You should probably NOT install it unless you know what you are doing. NO SUPPORT will be provided if this app doesn't work or breaks your system... If you are willing to take that risk anyway, type '{answers}'",
+    "confirm_app_install_insufficient_ram": "DANGER! This app requires {required} RAM to install/upgrade but only {current} is available right now. Even if this app could run, its installation process requires a large amount of RAM so your server may freeze and fail miserably. If you are willing to take that risk anyway, type '{answers}'",
     "confirm_app_install_thirdparty": "DANGER! This app is not part of YunoHost's app catalog. Installing third-party apps may compromise the integrity and security of your system. You should probably NOT install it unless you know what you are doing. NO SUPPORT will be provided if this app doesn't work or breaks your system... If you are willing to take that risk anyway, type '{answers}'",
     "confirm_app_install_warning": "Warning: This app may work, but is not well-integrated into YunoHost. Some features such as single sign-on and backup/restore might not be available. Install anyway? [{answers}] ",
     "custom_app_url_required": "You must provide a URL to upgrade your custom app {app}",

src/app.py

@@ -2418,18 +2418,18 @@ def _check_manifest_requirements(
 
     # Multi-instance
     if action == "install":
-        multi_instance = manifest["integration"]["multi_instance"] == True
+        multi_instance = manifest["integration"]["multi_instance"] is True
         if not multi_instance:
             apps = _installed_apps()
             sibling_apps = [
                 a for a in apps if a == app_id or a.startswith(f"{app_id}__")
             ]
-            multi_instance = len(sibling_apps) > 0
+            multi_instance = len(sibling_apps) == 0
 
         yield (
             "install",
             multi_instance,
-            {},
+            {"app": app_id},
             "app_already_installed",  # i18n: app_already_installed
         )