feat: hook ownership model with external manager detection

Cargo.toml

@@ -35,6 +35,7 @@ members = [
     # 👉mostly powered by legacy, but will help to transition to `but-db` backing.
     "crates/but-meta", # 📄An interface to support Git-entity metadata;
     # 👉lacks tests
+    "crates/but-hooks",           # 📄Git hook management: external manager detection and managed hook installation.
     "crates/but-hunk-assignment", # 📄Assign uncommitted changes to stacks/lanes.
     # 👉uses `but-ctx`.
     "crates/but-hunk-dependency", # 📄Assuming it works, it feels close to 'Exemplary',
@@ -156,6 +157,7 @@ but-worktrees = { path = "crates/but-worktrees" }
 but-db = { path = "crates/but-db" }
 but-path = { path = "crates/but-path" }
 but-graph = { path = "crates/but-graph" }
+but-hooks = { path = "crates/but-hooks" }
 but-meta = { path = "crates/but-meta" }
 but-rules = { path = "crates/but-rules" }
 but-action = { path = "crates/but-action" }
@@ -209,6 +211,7 @@ gitbutler-workspace = { path = "crates/gitbutler-workspace" }
 rusqlite = { version = "0.39.0", features = ["bundled"] }
 backoff = "0.4.0"
 bstr = "1.12.1"
+which = "8.0.0"
 # Add the `tracing` or `tracing-detail` features to see more of gitoxide in the logs. Useful to see which programs it invokes.
 # When adjusting this, update `gix-testtools` as well!
 gix = { version = "0.81.0", git = "https://github.com/GitoxideLabs/gitoxide", rev = "50fb46f17acba7d75d4ed6795b7b9cef484e34c6", default-features = false, features = [

crates/but-api/Cargo.toml

@@ -139,7 +139,7 @@ gix = { workspace = true, features = ["worktree-mutation"] }
 open.workspace = true
 url = { version = "2.5", optional = true }
 uuid.workspace = true
-which = "8.0.0"
+which.workspace = true
 but-schemars.workspace = true
 
 [dev-dependencies]

crates/but-core/src/lib.rs

@@ -114,7 +114,10 @@ mod ext;
 pub use ext::ObjectStorageExt;
 
 mod repo_ext;
-pub use repo_ext::{RepositoryExt, update_head_reference};
+pub use repo_ext::{
+    GITBUTLER_COMMIT_AUTHOR_EMAIL, GITBUTLER_COMMIT_AUTHOR_NAME, RepositoryExt, commit_time,
+    committer_signature, update_head_reference,
+};
 
 /// Return `true` if `ref_name` looks like the standard GitButler workspace.
 ///

crates/but-core/src/repo_ext.rs

@@ -468,12 +468,14 @@ impl RepositoryExt for gix::Repository {
     }
 }
 
-const GITBUTLER_COMMIT_AUTHOR_NAME: &str = "GitButler";
-const GITBUTLER_COMMIT_AUTHOR_EMAIL: &str = "gitbutler@gitbutler.com";
+/// The display name used for commits authored by GitButler itself.
+pub const GITBUTLER_COMMIT_AUTHOR_NAME: &str = "GitButler";
+/// The email address used for commits authored by GitButler itself.
+pub const GITBUTLER_COMMIT_AUTHOR_EMAIL: &str = "gitbutler@gitbutler.com";
 
 /// Provide a signature with the GitButler author, and the current time or the time overridden
 /// depending on the value for `purpose`.
-fn committer_signature() -> gix::actor::Signature {
+pub fn committer_signature() -> gix::actor::Signature {
     gix::actor::Signature {
         name: GITBUTLER_COMMIT_AUTHOR_NAME.into(),
         email: GITBUTLER_COMMIT_AUTHOR_EMAIL.into(),
@@ -483,7 +485,7 @@ fn committer_signature() -> gix::actor::Signature {
 
 /// Return the time of a commit as `now` unless the `overriding_variable_name` contains a parseable date,
 /// which is used instead.
-fn commit_time(overriding_variable_name: &str) -> gix::date::Time {
+pub fn commit_time(overriding_variable_name: &str) -> gix::date::Time {
     std::env::var(overriding_variable_name)
         .ok()
         .and_then(|time| gix::date::parse(&time, Some(std::time::SystemTime::now())).ok())

crates/but-hooks/Cargo.toml

@@ -0,0 +1,34 @@
+[package]
+name = "but-hooks"
+version = "0.0.0"
+edition.workspace = true
+publish = false
+rust-version.workspace = true
+
+[lib]
+doctest = false
+
+[features]
+## Enables env-var overrides for `is_binary_in_path` used by integration tests
+## to simulate binary presence/absence without touching the real PATH.
+## Must NOT be enabled in production builds.
+test-overrides = []
+
+[dependencies]
+but-core.workspace = true
+
+anyhow.workspace = true
+gix.workspace = true
+tracing.workspace = true
+which.workspace = true
+
+[[test]]
+name = "hooks"
+required-features = ["test-overrides"]
+
+[dev-dependencies]
+temp-env = "0.3"
+tempfile.workspace = true
+
+[lints]
+workspace = true