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- Remove outdated dependencies and update dependency versions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

branch/create_branch.rs

@@ -8,7 +8,10 @@ impl GitBare {
     pub fn create_branch(&self, request: CreateBranchRequest) -> GitResult<Branch> {
         crate::sanitize::validate_ref_name(&request.name)?;
         let revision = match request.start_point.and_then(|s| s.selector) {
-            Some(object_selector::Selector::Oid(oid)) => oid.hex,
+            Some(object_selector::Selector::Oid(oid)) => {
+                crate::sanitize::validate_oid_hex(&oid.hex)?;
+                oid.hex
+            }
             Some(object_selector::Selector::Revision(name)) => {
                 crate::sanitize::validate_revision(&name.revision)?;
                 name.revision

branch/get_branch.rs

@@ -4,6 +4,7 @@ use crate::pb::{Branch, GetBranchRequest};
 
 impl GitBare {
     pub fn get_branch(&self, request: GetBranchRequest) -> GitResult<Branch> {
+        crate::sanitize::validate_ref_name(&request.name)?;
         let repo = self.gix_repo()?;
         let refname = format!("refs/heads/{}", request.name);
         let mut r = repo.find_reference(refname.as_str())?;

branch/set_branch_upstream.rs

@@ -6,6 +6,8 @@ impl GitBare {
     pub fn set_branch_upstream(&self, request: SetBranchUpstreamRequest) -> GitResult<Branch> {
         crate::sanitize::validate_ref_name(&request.name)?;
         if let Some(upstream) = request.upstream {
+            crate::sanitize::validate_ref_name(&upstream.remote_name)?;
+            crate::sanitize::validate_ref_name(&upstream.remote_branch_name)?;
             let tracking = format!("{}/{}", upstream.remote_name, upstream.remote_branch_name);
             let result = duct::cmd(
                 "git",

branch/update_branch_target.rs

@@ -14,11 +14,13 @@ impl GitBare {
             .ok_or_else(|| GitError::InvalidArgument("new_oid is required".into()))?
             .hex
             .clone();
+        crate::sanitize::validate_oid_hex(&new_oid)?;
         let refname = format!("refs/heads/{}", request.name);
         let mut args = vec!["update-ref".to_string(), refname.clone(), new_oid];
         if !request.force
             && let Some(old) = request.expected_old_oid.as_ref()
         {
+            crate::sanitize::validate_oid_hex(&old.hex)?;
             args.push(old.hex.clone());
         }
         let output = Command::new("git")