Add Python init diagnostics, AppImage build system, misc Linux fixes

- python: switch Py_InitializeEx → Py_InitializeFromConfig for explicit
  error reporting; add dladdr + fprintf diagnostics to trace which DSO
  Python symbols resolve to and whether Py_IsInitialized succeeds
- python: log RTLD_NOLOAD vs fresh-load outcome when promoting libpython
  to RTLD_GLOBAL
- build: add Docker-based AppImage build script (build.sh), update
  Dockerfile and build-inner.sh for AppImage-only workflow
- build: remove Flatpak support entirely; move AppImage metadata
  (desktop/metainfo/icon) from flatpak/ to data/
- Add Monster Hunter Wilds basic_games plugin
- .gitignore: exclude squashfs-root, build-source, flatpak-repo,
  __pycache__, fomod-plus-settings.ini
- Various Linux port fixes across wineprefix, processrunner, proton
  launcher, FUSE connector, instance manager, download manager,
  sanitychecks, and NaK Rust paths/runtime_wrap

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

3 files changed, 60 insertions, 0 deletions

diff --git a/data/com.fluorine.manager.desktop b/data/com.fluorine.manager.desktop
new file mode 100644
index 0000000..ff62c76
--- /dev/null
+++ b/data/com.fluorine.manager.desktop
@@ -0,0 +1,22 @@
+[Desktop Entry]
+Type=Application
+Name=Fluorine Manager
+GenericName=Mod Manager
+Comment=Mod Organizer 2 for Linux - manage your game mods
+Exec=fluorine-manager
+Icon=com.fluorine.manager
+Terminal=false
+Categories=Game;Utility;
+Keywords=mod;organizer;modding;skyrim;fallout;
+MimeType=x-scheme-handler/nxm;
+Actions=create-portable;list-instances;
+
+[Desktop Action create-portable]
+Name=Create Portable Instance
+Exec=fluorine-manager create-portable
+Icon=com.fluorine.manager
+
+[Desktop Action list-instances]
+Name=List Instances
+Exec=fluorine-manager list-instances
+Icon=com.fluorine.manager
diff --git a/data/com.fluorine.manager.metainfo.xml b/data/com.fluorine.manager.metainfo.xml
new file mode 100644
index 0000000..1200d3e
--- /dev/null
+++ b/data/com.fluorine.manager.metainfo.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<component type="desktop-application">
+  <id>com.fluorine.manager</id>
+  <name>Fluorine Manager</name>
+  <summary>Mod Organizer 2 for Linux</summary>
+  <metadata_license>CC0-1.0</metadata_license>
+  <project_license>GPL-3.0-or-later</project_license>
+
+  <description>
+    <p>
+      Fluorine Manager is a Linux port of Mod Organizer 2, a powerful mod management
+      tool for Bethesda games and other titles. It uses a virtual filesystem to keep
+      your game directory clean while allowing complex mod setups with load order
+      management, conflict resolution, and profile support.
+    </p>
+    <p>Features:</p>
+    <ul>
+      <li>Virtual filesystem - mods never touch your game folder</li>
+      <li>Profile system for different mod configurations</li>
+      <li>Plugin load order management</li>
+      <li>Mod conflict detection and resolution</li>
+      <li>Nexus Mods integration for downloading</li>
+      <li>Proton/Wine prefix management for running Windows games</li>
+      <li>UMU launcher support</li>
+    </ul>
+  </description>
+
+  <launchable type="desktop-id">com.fluorine.manager.desktop</launchable>
+
+  <url type="homepage">https://github.com/ModOrganizer2/modorganizer</url>
+  <url type="bugtracker">https://github.com/ModOrganizer2/modorganizer/issues</url>
+
+  <provides>
+    <binary>fluorine-manager</binary>
+  </provides>
+
+  <content_rating type="oars-1.1" />
+</component>
diff --git a/data/com.fluorine.manager.png b/data/com.fluorine.manager.png
new file mode 100644
index 0000000..3a9fbdd
--- /dev/null
+++ b/data/com.fluorine.manager.png