refactor(cache): redesign cache system with structured keys and improved performance

- Add repo_path parameter to cached_response and cached_vec_response functions
- Implement structured cache key format with namespace, repo_path, and request proto
- Replace global cache with Moka in-memory cache using weight-based eviction
- Set 256MB memory cap with 10-minute TTL and 2-minute TTI policy
- Add metrics collection for cache operations and evictions
- Implement efficient repo-scoped invalidation using key structure
- Add detailed documentation comments explaining cache architecture
- Remove outdated dependencies and update dependency versions
- Add error handling for encoding failures in cache operations
- Optimize Vec responses with length-delimited encoding and pre-allocation

snapshot/ops.rs

@@ -81,7 +81,7 @@ pub fn create_and_store_snapshot(
 pub fn restore_snapshot(repo_path: &Path, data: &[u8]) -> GitResult<()> {
     tracing::info!(path = %repo_path.display(), size_bytes = data.len(), "restoring snapshot");
 
-    let applicator = crate::actor::sync::BundleApplicator::new(repo_path.to_path_buf());
+    let applicator = crate::snapshot::sync::BundleApplicator::new(repo_path.to_path_buf());
     applicator.apply_bundle(data).map_err(GitError::Internal)?;
 
     tracing::info!(path = %repo_path.display(), "snapshot restored");
@@ -163,7 +163,7 @@ fn generate_snapshot_id(relative_path: &str, head_oid: &str) -> String {
     let mut s = String::with_capacity(16);
     for byte in &hash[..8] {
         use std::fmt::Write;
-        write!(s, "{byte:02x}").unwrap();
+        let _ = write!(s, "{byte:02x}");
     }
     s
 }