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>

arma_modlist_tools/compat.py

@@ -0,0 +1,108 @@
+"""
+arma_modlist_tools.compat
+~~~~~~~~~~~~~~~~~~~~~~~~~
+OS detection and cross-platform utilities shared by all CLI scripts.
+
+Supported platforms:
+  - Windows / Windows Server  (sys.platform == "win32")
+  - Ubuntu / Ubuntu Server    (sys.platform == "linux")
+
+Typical usage::
+
+    from arma_modlist_tools.compat import is_windows, get_os_label, fix_console_encoding
+
+    fix_console_encoding()   # call once at script start on Windows
+    print(get_os_label())    # "Windows Server", "Ubuntu", etc.
+"""
+
+from __future__ import annotations
+
+import io
+import platform
+import sys
+
+
+# ---------------------------------------------------------------------------
+# Platform detection
+# ---------------------------------------------------------------------------
+
+def is_windows() -> bool:
+    """Return ``True`` on Windows and Windows Server."""
+    return sys.platform == "win32"
+
+
+def is_linux() -> bool:
+    """Return ``True`` on Linux (Ubuntu, Ubuntu Server, and other distros)."""
+    return sys.platform == "linux"
+
+
+def get_os_label() -> str:
+    """
+    Return a human-readable OS label.
+
+    Possible values: ``"Windows"``, ``"Windows Server"``, ``"Ubuntu"``,
+    ``"Ubuntu Server"``, ``"Linux"``, ``"Unknown"``.
+    """
+    if is_windows():
+        ver = platform.version()
+        # Windows Server versions contain "Server" in the version string
+        # e.g. "10.0.17763 ... Windows Server 2019 ..."
+        if "Server" in platform.version() or "Server" in platform.uname().version:
+            return "Windows Server"
+        return "Windows"
+
+    if is_linux():
+        # Read /etc/os-release for distro name
+        os_release = _read_os_release()
+        name = os_release.get("NAME", "").lower()
+
+        if "ubuntu" in name:
+            # Distinguish desktop vs server: server images have no display server
+            if _is_headless():
+                return "Ubuntu Server"
+            return "Ubuntu"
+
+        return "Linux"
+
+    return "Unknown"
+
+
+def _read_os_release() -> dict[str, str]:
+    """Parse /etc/os-release into a dict (Linux only)."""
+    result: dict[str, str] = {}
+    try:
+        with open("/etc/os-release", encoding="utf-8") as f:
+            for line in f:
+                line = line.strip()
+                if "=" in line and not line.startswith("#"):
+                    k, _, v = line.partition("=")
+                    result[k] = v.strip('"')
+    except OSError:
+        pass
+    return result
+
+
+def _is_headless() -> bool:
+    """Return True if no graphical display server is detected (headless/server)."""
+    import os
+    # Check for common display environment variables
+    return not (os.environ.get("DISPLAY") or os.environ.get("WAYLAND_DISPLAY"))
+
+
+# ---------------------------------------------------------------------------
+# Console encoding
+# ---------------------------------------------------------------------------
+
+def fix_console_encoding() -> None:
+    """
+    Force UTF-8 output on Windows terminals that default to cp1252.
+
+    Call once at the top of any CLI script that uses Unicode characters
+    (checkmarks, arrows, etc.).  No-op on Linux.
+    """
+    if not is_windows():
+        return
+    if sys.stdout.encoding and sys.stdout.encoding.lower() == "utf-8":
+        return
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding="utf-8", errors="replace")
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding="utf-8", errors="replace")