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>

1 files changed, 15 insertions, 6 deletions

diff --git a/.gitignore b/.gitignore
index da898a0..96bb944 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,12 +7,8 @@ build-container-2404-gcc14/
 # Rust build artifacts
 target/
 
-# Flatpak build cache and artifacts
-.flatpak-builder/
-.flatpak-build/
-flatpak-repo/
-flatpak/builddir/
-*.flatpak
+# AppImage build artifacts
+*.AppImage
 
 # Logs
 *.log
@@ -26,3 +22,16 @@ compile_commands.json
 # OS junk
 .DS_Store
 Thumbs.db
+
+# AppImage extraction/build leftovers
+squashfs-root/
+build-source/
+flatpak-repo/
+*.flatpak
+
+# Python bytecode
+__pycache__/
+*.pyc
+
+# Generated settings files
+fomod-plus-settings.ini