chore: merge git crates (#5909)

Merge `git-apply` and `git-tooling` into `utils/`

codex-rs/utils/git/src/lib.rs

@@ -0,0 +1,79 @@
+use std::fmt;
+use std::path::PathBuf;
+
+mod apply;
+mod errors;
+mod ghost_commits;
+mod operations;
+mod platform;
+
+pub use apply::ApplyGitRequest;
+pub use apply::ApplyGitResult;
+pub use apply::apply_git_patch;
+pub use apply::extract_paths_from_patch;
+pub use apply::parse_git_apply_output;
+pub use apply::stage_paths;
+pub use errors::GitToolingError;
+pub use ghost_commits::CreateGhostCommitOptions;
+pub use ghost_commits::create_ghost_commit;
+pub use ghost_commits::restore_ghost_commit;
+pub use ghost_commits::restore_to_commit;
+pub use platform::create_symlink;
+use schemars::JsonSchema;
+use serde::Deserialize;
+use serde::Serialize;
+use ts_rs::TS;
+
+type CommitID = String;
+
+/// Details of a ghost commit created from a repository state.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, TS)]
+pub struct GhostCommit {
+    id: CommitID,
+    parent: Option<CommitID>,
+    preexisting_untracked_files: Vec<PathBuf>,
+    preexisting_untracked_dirs: Vec<PathBuf>,
+}
+
+impl GhostCommit {
+    /// Create a new ghost commit wrapper from a raw commit ID and optional parent.
+    pub fn new(
+        id: CommitID,
+        parent: Option<CommitID>,
+        preexisting_untracked_files: Vec<PathBuf>,
+        preexisting_untracked_dirs: Vec<PathBuf>,
+    ) -> Self {
+        Self {
+            id,
+            parent,
+            preexisting_untracked_files,
+            preexisting_untracked_dirs,
+        }
+    }
+
+    /// Commit ID for the snapshot.
+    pub fn id(&self) -> &str {
+        &self.id
+    }
+
+    /// Parent commit ID, if the repository had a `HEAD` at creation time.
+    pub fn parent(&self) -> Option<&str> {
+        self.parent.as_deref()
+    }
+
+    /// Untracked or ignored files that already existed when the snapshot was captured.
+    pub fn preexisting_untracked_files(&self) -> &[PathBuf] {
+        &self.preexisting_untracked_files
+    }
+
+    /// Untracked or ignored directories that already existed when the snapshot was captured.
+    pub fn preexisting_untracked_dirs(&self) -> &[PathBuf] {
+        &self.preexisting_untracked_dirs
+    }
+}
+
+impl fmt::Display for GhostCommit {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.id)
+    }
+}