Initial release: full Arma 3 mod management toolchain

Pipeline: parse HTML presets, compare modlists, download from Caddy
file server, create junctions/symlinks to Arma 3 Server directory.
Includes update/sync flows, missing-mod reporting, OS compat layer,
shared config, dep checker, comprehensive test suite (71 tests).

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

.gitignore

@@ -0,0 +1,33 @@
+# Credentials — never commit
+config.json
+
+# Generated output
+modlist_json/
+downloads/
+
+# Python
+__pycache__/
+*.py[cod]
+*.pyo
+*.pyd
+.Python
+*.egg-info/
+dist/
+build/
+.eggs/
+
+# Virtual environments
+venv/
+.venv/
+env/
+
+# Editor / OS
+.vscode/
+.idea/
+*.swp
+*.swo
+.DS_Store
+Thumbs.db
+
+# Claude Code local settings
+.claude/