extension: move git attribution into an extension

codex-rs/app-server/Cargo.toml

@@ -41,6 +41,7 @@ codex-extension-api = { workspace = true }
 codex-external-agent-migration = { workspace = true }
 codex-external-agent-sessions = { workspace = true }
 codex-features = { workspace = true }
+codex-git-attribution = { workspace = true }
 codex-git-utils = { workspace = true }
 codex-hooks = { workspace = true }
 codex-otel = { workspace = true }

codex-rs/app-server/src/extensions.rs

@@ -5,5 +5,9 @@ use codex_extension_api::ExtensionRegistry;
 use codex_extension_api::ExtensionRegistryBuilder;
 
 pub(crate) fn thread_extensions() -> Arc<ExtensionRegistry<Config>> {
-    Arc::new(ExtensionRegistryBuilder::<Config>::new().build())
+    Arc::new(
+        ExtensionRegistryBuilder::<Config>::new()
+            .with_extension(codex_git_attribution::extension())
+            .build(),
+    )
 }