Unpatch saves started with save patching disabled

Turning factorio.enable_save_patching off did nothing to a save that
was patched before. Its control.lua still loaded every module, so the
clusterio_api interface, player_sync's join handling and the other
module event handlers kept running with no plugin on the host side.

When patching is disabled the instance now restores the original
control.lua that patching kept as scenario.lua and removes the module
files, locale files included, as listed in clusterio.json. The patch
info stays with an empty module list so the patch number keeps
counting. Otherwise patching the save again would reuse the number
stored in the game and on_server_startup would not be raised. Data
the modules put in storage is left alone.

PatchInfo.fromSave dropped the version read from the save, so the
check against newer patch versions never fired. It now keeps it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/configuration.md

@@ -639,6 +639,8 @@ Most plugins require the use of save patching to function.
 Turning it off makes it possible to use Clusterio to run and manage regular vanilla games and scenarios not compatible with Clusterio.
 Plugins that need save patching can't be loaded on the instance while this is disabled.
 Disabling it while such a plugin is loaded is rejected, and so is loading such a plugin while it is disabled.
+Saves patched before are restored to their original control.lua and have the modules removed when started with this disabled.
+Data the modules stored in the game is left in place.
 
 Defaults to true.
 

docs/how-it-works.md

@@ -27,6 +27,7 @@ The save patching is based on the built in [event_handler](https://github.com/wu
 Mods on the other hand work without modifications.
 
 This can be disabled with the `factorio.enable_save_patching` config on a per instance basis, however disabling it means that modules are not loaded into the game and most plugins will not function.
+A save that was patched before has its modules removed again when it's started with save patching disabled.
 To use the modules outside of Clusterio the `npx clusteriohost create-scenario` command creates a scenario with the modules patched into it.
 Note that the IPC between the game and the host is not available outside of Clusterio, so modules that depend on it will not work as expected in such a scenario.