feat(server): add tracing spans and caching to archive and blame services

- Add tracing spans with repo labels for archive and blame operations
- Implement caching for archive list entries when using OID selectors
- Implement caching for blame operations when using OID selectors
- Add detailed

main.rs

@@ -10,17 +10,25 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     dotenvy::dotenv().ok();
     tracing_subscriber::fmt::init();
 
+    tracing::info!(
+        version = env!("CARGO_PKG_VERSION"),
+        "gitks starting up"
+    );
+
     let host = std::env::var("GITKS_HOST").unwrap_or_else(|_| DEFAULT_HOST.into());
     let port = std::env::var("GITKS_PORT").unwrap_or_else(|_| DEFAULT_PORT.into());
 
-    let repo_prefix = std::env::var("REPO_PREFIX_PATH").map_err(|_| {
-        "REPO_PREFIX_PATH environment variable is required (e.g. /data/repos)"
-    })?;
+    let repo_prefix = std::env::var("REPO_PREFIX_PATH")
+        .map_err(|_| "REPO_PREFIX_PATH environment variable is required (e.g. /data/repos)")?;
     let repo_prefix = PathBuf::from(&repo_prefix);
     if !repo_prefix.is_absolute() {
         return Err("REPO_PREFIX_PATH must be an absolute path".into());
     }
     if !repo_prefix.exists() {
+        tracing::info!(
+            path = %repo_prefix.display(),
+            "creating repo prefix directory"
+        );
         std::fs::create_dir_all(&repo_prefix)?;
     }
 
@@ -33,5 +41,6 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     serve(addr, repo_prefix).await?;
 
+    tracing::info!("gitks shut down");
     Ok(())
 }