feat(git): add advanced clone options (shallow, sparse, flags)

Add advanced clone options support across the frontend and backend.
Users can specify a branch, shallow limits, blobless mode, sparse paths,
and custom clone flags when initiating a clone operation. The backend
validates inputs, parses custom flags without invoking a shell, and
configures sparse checkouts after a successful clone. A small parsing
dependency was added and tracked-file parsing was improved to better
handle git ls-files output.

- Introduce CloneRunOptions and validation helpers for clone inputs
- Parse custom flags with a shell-like tokenizer and block managed flags
- Support sparse checkout configuration and shallow clone constraints

src-tauri/Cargo.toml

@@ -24,6 +24,7 @@ tokio = { version = "1.52.3", features = ["macros", "rt-multi-thread"] }
 log = "0.4"
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "json", "rustls-tls"] }
 sysinfo = { version = "=0.38.3", default-features = false, features = ["system"] }
+shlex = "2"
 
 [build-dependencies]
 tauri-build = { version = "2", features = [] }