feat(ltk-mod-lib): add new mod lib abstraction

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "crates/ltk_mod_project",
     "crates/ltk_overlay",
     "crates/ltk_pki",
+    "crates/ltk_mod_lib",
 ]
 
 [workspace.dependencies]

crates/ltk_mod_lib/Cargo.toml

@@ -0,0 +1,34 @@
+[package]
+name = "ltk_mod_lib"
+version = "0.1.0"
+edition = "2021"
+description = "Mod library management for LeagueToolkit — install, profiles, overlay orchestration"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/LeagueToolkit/league-mod"
+homepage = "https://github.com/LeagueToolkit/league-mod"
+readme = "../../README.md"
+keywords = ["league-of-legends", "modding", "gaming", "toolkit"]
+categories = ["game-development"]
+authors = ["LeagueToolkit"]
+
+[dependencies]
+ltk_overlay = { version = "0.2.3", path = "../ltk_overlay" }
+ltk_modpkg = { version = "0.3.2", path = "../ltk_modpkg", features = ["project"] }
+ltk_mod_project = { version = "0.3.0", path = "../ltk_mod_project" }
+ltk_fantome = { version = "0.4.0", path = "../ltk_fantome" }
+ltk_mod_core = { version = "0.1.0", path = "../ltk_mod_core" }
+
+camino = { workspace = true }
+
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+thiserror = "2"
+chrono = { version = "0.4", features = ["serde"] }
+uuid = { version = "1", features = ["v4"] }
+slug = "0.1"
+zip = "2"
+tracing = "0.1"
+fs2 = "0.4"
+
+[dev-dependencies]
+tempfile = "3"

crates/ltk_mod_lib/src/error.rs

@@ -0,0 +1,41 @@
+/// Library-specific error types with no Tauri dependency.
+#[derive(Debug, thiserror::Error)]
+pub enum LibraryError {
+    #[error("IO error: {0}")]
+    Io(#[from] std::io::Error),
+
+    #[error("JSON error: {0}")]
+    Json(#[from] serde_json::Error),
+
+    #[error("Modpkg error: {0}")]
+    Modpkg(#[from] ltk_modpkg::error::ModpkgError),
+
+    #[error("Fantome error: {0}")]
+    Fantome(String),
+
+    #[error("Mod not found: {0}")]
+    ModNotFound(String),
+
+    #[error("Invalid path: {0}")]
+    InvalidPath(String),
+
+    #[error("Validation failed: {0}")]
+    ValidationFailed(String),
+
+    #[error("Storage locked by another process")]
+    StorageLocked,
+
+    #[error("Library index is corrupt: {0}")]
+    IndexCorrupt(String),
+
+    #[error("ZIP error: {0}")]
+    Zip(#[from] zip::result::ZipError),
+
+    #[error("Overlay build failed: {0}")]
+    OverlayFailed(String),
+
+    #[error("{0}")]
+    Other(String),
+}
+
+pub type LibraryResult<T> = Result<T, LibraryError>;