Add FUSE external mapping support, BG3/Oblivion Remastered fixes, fomod-plus and NaK integration

FUSE VFS now deploys non-data-dir mod mappings (Paks, OBSE, UE4SS, etc.)
via real symlinks and injects file-level data-dir mappings (plugins.txt,
loadorder.txt) into the VFS tree. Fixes game launches for Oblivion
Remastered (Root Builder path resolution, script extender support) and
BG3 (Wine prefix documents directory, file mapper symlinks on Linux).

Vendors mo2-fomod-plus plugin and NaK crate for FOMOD installer and
game finder/runtime support.

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

1 files changed, 245 insertions, 0 deletions

diff --git a/libs/nak/src/game_finder/known_games.rs b/libs/nak/src/game_finder/known_games.rs
new file mode 100644
index 0000000..8a30c18
--- /dev/null
+++ b/libs/nak/src/game_finder/known_games.rs
@@ -0,0 +1,245 @@
+//! Known games configuration
+//!
+//! Contains metadata for games that NaK supports, including:
+//! - Steam App ID
+//! - My Games folder name (Documents/My Games/*)
+//! - AppData/Local folder name
+//! - Registry path for game detection
+
+/// Configuration for a known game
+#[derive(Debug, Clone)]
+pub struct KnownGame {
+    /// Display name
+    pub name: &'static str,
+    /// Steam App ID
+    pub steam_app_id: &'static str,
+    /// GOG App ID (if available)
+    pub gog_app_id: Option<&'static str>,
+    /// Folder name in Documents/My Games (if applicable)
+    pub my_games_folder: Option<&'static str>,
+    /// Folder name in AppData/Local (if applicable)
+    pub appdata_local_folder: Option<&'static str>,
+    /// Folder name in AppData/Roaming (if applicable)
+    pub appdata_roaming_folder: Option<&'static str>,
+    /// Registry path under HKLM\Software\ (for game detection)
+    pub registry_path: &'static str,
+    /// Registry value name for install path
+    pub registry_value: &'static str,
+    /// Expected folder name in steamapps/common/
+    pub steam_folder: &'static str,
+}
+
+/// All known games that NaK supports
+pub const KNOWN_GAMES: &[KnownGame] = &[
+    // Bethesda Games
+    KnownGame {
+        name: "Enderal",
+        steam_app_id: "933480",
+        gog_app_id: None,
+        my_games_folder: Some("Enderal"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\SureAI\Enderal",
+        registry_value: "Install_Path",
+        steam_folder: "Enderal",
+    },
+    KnownGame {
+        name: "Enderal Special Edition",
+        steam_app_id: "976620",
+        gog_app_id: None,
+        my_games_folder: Some("Enderal Special Edition"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\SureAI\Enderal SE",
+        registry_value: "installed path",
+        steam_folder: "Enderal Special Edition",
+    },
+    KnownGame {
+        name: "Fallout 3",
+        steam_app_id: "22300",
+        gog_app_id: Some("1454315831"), // Fallout 3 GOTY
+        my_games_folder: Some("Fallout3"),
+        appdata_local_folder: Some("Fallout3"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Fallout3",
+        registry_value: "Installed Path",
+        steam_folder: "Fallout 3",
+    },
+    KnownGame {
+        name: "Fallout 4",
+        steam_app_id: "377160",
+        gog_app_id: None,
+        my_games_folder: Some("Fallout4"),
+        appdata_local_folder: Some("Fallout4"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Fallout4",
+        registry_value: "Installed Path",
+        steam_folder: "Fallout 4",
+    },
+    KnownGame {
+        name: "Fallout 4 VR",
+        steam_app_id: "611660",
+        gog_app_id: None,
+        my_games_folder: Some("Fallout4VR"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Fallout 4 VR",
+        registry_value: "Installed Path",
+        steam_folder: "Fallout 4 VR",
+    },
+    KnownGame {
+        name: "Fallout New Vegas",
+        steam_app_id: "22380",
+        gog_app_id: Some("1454587428"), // Fallout NV Ultimate
+        my_games_folder: Some("FalloutNV"),
+        appdata_local_folder: Some("FalloutNV"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\FalloutNV",
+        registry_value: "Installed Path",
+        steam_folder: "Fallout New Vegas",
+    },
+    KnownGame {
+        name: "Morrowind",
+        steam_app_id: "22320",
+        gog_app_id: Some("1440163901"), // Morrowind GOTY
+        my_games_folder: Some("Morrowind"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Morrowind",
+        registry_value: "Installed Path",
+        steam_folder: "Morrowind",
+    },
+    KnownGame {
+        name: "Oblivion",
+        steam_app_id: "22330",
+        gog_app_id: Some("1458058109"), // Oblivion GOTY Deluxe
+        my_games_folder: Some("Oblivion"),
+        appdata_local_folder: Some("Oblivion"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Oblivion",
+        registry_value: "Installed Path",
+        steam_folder: "Oblivion",
+    },
+    KnownGame {
+        name: "Skyrim",
+        steam_app_id: "72850",
+        gog_app_id: None, // Not on GOG
+        my_games_folder: Some("Skyrim"),
+        appdata_local_folder: Some("Skyrim"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Skyrim",
+        registry_value: "Installed Path",
+        steam_folder: "Skyrim",
+    },
+    KnownGame {
+        name: "Skyrim Special Edition",
+        steam_app_id: "489830",
+        gog_app_id: Some("1711230643"), // Skyrim SE Anniversary Edition
+        my_games_folder: Some("Skyrim Special Edition"),
+        appdata_local_folder: Some("Skyrim Special Edition"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Skyrim Special Edition",
+        registry_value: "Installed Path",
+        steam_folder: "Skyrim Special Edition",
+    },
+    KnownGame {
+        name: "Skyrim VR",
+        steam_app_id: "611670",
+        gog_app_id: None,
+        my_games_folder: Some("Skyrim VR"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Skyrim VR",
+        registry_value: "Installed Path",
+        steam_folder: "Skyrim VR",
+    },
+    KnownGame {
+        name: "Starfield",
+        steam_app_id: "1716740",
+        gog_app_id: None,
+        my_games_folder: Some("Starfield"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Bethesda Softworks\Starfield",
+        registry_value: "Installed Path",
+        steam_folder: "Starfield",
+    },
+    // CD Projekt RED Games
+    KnownGame {
+        name: "The Witcher 3",
+        steam_app_id: "292030",
+        gog_app_id: Some("1495134320"), // Witcher 3 GOTY
+        my_games_folder: Some("The Witcher 3"),
+        appdata_local_folder: None,
+        appdata_roaming_folder: None,
+        registry_path: r"Software\CD Projekt Red\The Witcher 3",
+        registry_value: "InstallFolder",
+        steam_folder: "The Witcher 3 Wild Hunt",
+    },
+    KnownGame {
+        name: "Cyberpunk 2077",
+        steam_app_id: "1091500",
+        gog_app_id: Some("1423049311"),
+        my_games_folder: None,
+        appdata_local_folder: Some("CD Projekt Red/Cyberpunk 2077"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\CD Projekt Red\Cyberpunk 2077",
+        registry_value: "InstallFolder",
+        steam_folder: "Cyberpunk 2077",
+    },
+    // Other popular moddable games
+    KnownGame {
+        name: "Baldur's Gate 3",
+        steam_app_id: "1086940",
+        gog_app_id: Some("1456460669"),
+        my_games_folder: None,
+        appdata_local_folder: Some("Larian Studios/Baldur's Gate 3"),
+        appdata_roaming_folder: None,
+        registry_path: r"Software\Larian Studios\Baldur's Gate 3",
+        registry_value: "InstallDir",
+        steam_folder: "Baldurs Gate 3",
+    },
+];
+
+/// Find a known game by Steam App ID
+pub fn find_by_steam_id(app_id: &str) -> Option<&'static KnownGame> {
+    let normalized_id = normalize_steam_id(app_id);
+    KNOWN_GAMES.iter().find(|g| g.steam_app_id == normalized_id)
+}
+
+/// Find a known game by GOG App ID
+pub fn find_by_gog_id(app_id: &str) -> Option<&'static KnownGame> {
+    KNOWN_GAMES
+        .iter()
+        .find(|g| g.gog_app_id == Some(app_id))
+}
+
+/// Find a known game by name (case-insensitive)
+pub fn find_by_name(name: &str) -> Option<&'static KnownGame> {
+    let name_lower = name.to_lowercase();
+    KNOWN_GAMES
+        .iter()
+        .find(|g| g.name.to_lowercase() == name_lower)
+}
+
+/// Normalize Steam App IDs that have equivalent variants.
+fn normalize_steam_id(app_id: &str) -> &str {
+    match app_id {
+        // Fallout 3 often appears as GOTY App ID 22370.
+        // We treat it as Fallout 3 for shared metadata/registry mapping.
+        "22370" => "22300",
+        _ => app_id,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::find_by_steam_id;
+
+    #[test]
+    fn fallout_3_goty_alias_maps_to_fallout_3() {
+        let game = find_by_steam_id("22370").expect("22370 should map to Fallout 3");
+        assert_eq!(game.name, "Fallout 3");
+        assert_eq!(game.steam_app_id, "22300");
+    }
+}