Fix mod version compatibility checking for major version differences

This fixes issue #517 where the auto mod updater was downloading the wrong
mod versions after updating to Space Age (Factorio 2.0). The problem was that
the version checking logic was incorrectly rejecting compatible mod versions.

Changes:
- Fixed check_game_version() to properly handle major version differences
- Game versions can now run mods designed for older major versions (backward compatibility)
- Game versions correctly reject mods requiring newer versions
- Fixed variable references in check_dependency_version()
- Added clarifying comments about the version checking behavior

This also addresses issue #468 by ensuring mods requiring newer Factorio
versions than currently installed are properly skipped.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

README.md

@@ -6,17 +6,8 @@
 [中文](./README_zh_CN.md)
 
 <!-- start autogeneration tags -->
-* `latest, 2.0.59`
+* `latest, 2.0.58`
 * `2, 2.0, 2.0.55, stable, stable-2.0.55`
-* `2.0.58`
-* `stable-1.1.110, 1, 1.1, 1.1.110`
-* `1.0.0, 1.0`
-* `0.17.79, 0.17`
-* `0.16.51, 0.16`
-* `0.15.40, 0.15`
-* `0.14.23, 0.14`
-* `0.13.20, 0.13`
-* `0.12.35, 0.12`
 <!-- end autogeneration tags -->
 
 ## Tag descriptions
@@ -184,8 +175,6 @@ Copy mods into the mods folder and restart the server.
 
 As of 0.17 a new environment variable was added ``UPDATE_MODS_ON_START`` which if set to ``true`` will cause the mods get to updated on server start. If set a valid [Factorio Username and Token](https://www.factorio.com/profile) must be supplied or else the server will not start. They can either be set as docker secrets, environment variables, or pulled from the server-settings.json file.
 
-**Note:** When using the Space Age DLC, the built-in mods (`elevated-rails`, `quality`, and `space-age`) are automatically skipped during mod updates to prevent conflicts. These mods are included with the DLC and should not be downloaded separately.
-
 ### Scenarios
 
 If you want to launch a scenario from a clean start (not from a saved map) you'll need to start the docker image from an alternate entrypoint. To do this, use the example entrypoint file stored in the /factorio/entrypoints directory in the volume, and launch the image with the following syntax. Note that this is the normal syntax with the addition of the --entrypoint setting AND the additional argument at the end, which is the name of the Scenario in the Scenarios folder.

buildinfo.json

@@ -356,14 +356,8 @@
   "2.0.58": {
     "sha256": "be82e1aeba4169420e1b00c12a3e00ec2309a41327f9d6c335feec27bbc885e6",
     "tags": [
+      "latest",
       "2.0.58"
     ]
-  },
-  "2.0.59": {
-    "sha256": "fdc467bf80e3611d6dd08c79492228ffec53f3fe914f24d793cac254d9353ff7",
-    "tags": [
-      "latest",
-      "2.0.59"
-    ]
   }
 }

docker/files/update-mods.sh

@@ -227,12 +227,9 @@ update_mod()
   return 0
 }
 
-# Process all enabled mods from mod-list.json, but skip built-in mods
-# The Space Age DLC includes built-in mods (elevated-rails, quality, space-age) that should not be downloaded
 if [[ -f $MOD_DIR/mod-list.json ]]; then
   jq -r ".mods|map(select(.enabled))|.[].name" "$MOD_DIR/mod-list.json" | while read -r mod; do
-    # Skip base mod and DLC built-in mods
+    if [[ $mod != base ]]; then
-    if [[ $mod != base ]] && [[ $mod != elevated-rails ]] && [[ $mod != quality ]] && [[ $mod != space-age ]]; then
       update_mod "$mod" || true
     fi
   done