refactor(promise): rewrite promise bodies to async/await

Mechanically convert promise-returning function bodies to async/await:
resolve() returns the value directly, forwarding calls get .await, and
simple .then chains become await sequences. Also collapse the installer
double-Option (Result<Option<Option<PhpMixed>>> -> Result<Option<PhpMixed>>).

Hard spots that depend on the Loop::wait / job-machine boundary
(accept/reject orchestration, closures capturing &mut self, batch waits)
are left intact and marked with TODO(phase-c-promise) for manual porting.
The crate does not compile yet; traits still need #[async_trait].

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

1 files changed, 14 insertions, 8 deletions

diff --git a/crates/shirabe/src/downloader/rar_downloader.rs b/crates/shirabe/src/downloader/rar_downloader.rs
index 71efc29..c6031d9 100644
--- a/crates/shirabe/src/downloader/rar_downloader.rs
+++ b/crates/shirabe/src/downloader/rar_downloader.rs
@@ -77,7 +77,7 @@ impl RarDownloader {
                 (),
             )? == 0
             {
-                return Ok(shirabe_external_packages::react::promise::resolve(None));
+                return Ok(None);
             }
 
             process_error = Some(format!(
@@ -139,7 +139,7 @@ impl RarDownloader {
 
         rar_archive.close();
 
-        Ok(shirabe_external_packages::react::promise::resolve(None))
+        Ok(None)
     }
 }
 
@@ -155,7 +155,9 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         prev_package: Option<&dyn PackageInterface>,
         output: bool,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.download(package, path, prev_package, output)
+        self.inner
+            .download(package, path, prev_package, output)
+            .await
     }
 
     async fn prepare(
@@ -165,7 +167,9 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         path: &str,
         prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.prepare(r#type, package, path, prev_package)
+        self.inner
+            .prepare(r#type, package, path, prev_package)
+            .await
     }
 
     async fn install(
@@ -174,7 +178,7 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         path: &str,
         output: bool,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.install(package, path, output)
+        self.inner.install(package, path, output).await
     }
 
     async fn update(
@@ -183,7 +187,7 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         target: &dyn PackageInterface,
         path: &str,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.update(initial, target, path)
+        self.inner.update(initial, target, path).await
     }
 
     async fn remove(
@@ -192,7 +196,7 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         path: &str,
         output: bool,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.remove(package, path, output)
+        self.inner.remove(package, path, output).await
     }
 
     async fn cleanup(
@@ -202,6 +206,8 @@ impl crate::downloader::DownloaderInterface for RarDownloader {
         path: &str,
         prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.cleanup(r#type, package, path, prev_package)
+        self.inner
+            .cleanup(r#type, package, path, prev_package)
+            .await
     }
 }