refactor(server): replace custom remote clients with macro-based implementation

- Replaced manual remote client functions with remote_client! macro for archive, blame, branch, commit, and diff services
- Simplified remote client creation logic using declarative macro approach
- Maintained same functionality while reducing code duplication across services

security(bare): enhance path traversal protection with comprehensive validation

- Added early relative_path validation to prevent path traversal attacks
- Implemented unified path validation to avoid TOCTOU race conditions
- Enhanced canonicalization checks for both existing and non-existent paths
- Added detailed logging for path traversal detection attempts

feat(cache): migrate from CLruCache to Moka with TTL and invalidation support

- Replaced clru dependency with moka for improved caching capabilities
- Added 300-second time-to-live for cache entries
- Implemented repository-specific cache invalidation mechanism
- Enhanced cache operations with thread-safe async support

refactor(commit): improve security validation for commit operations

- Added ref name validation to prevent command injection in cherry_pick_commit
- Implemented revision validation for commit selectors
- Added comprehensive input validation for create_commit parameters
- Enhanced file path validation to prevent traversal

macros.rs

@@ -0,0 +1,36 @@
+//! Helper macro to extract and validate a revision selector.
+//!
+//! Replaces the repeated pattern of matching on ObjectSelector variants
+//! and validating revision strings before use.
+
+/// Extract a revision string from an optional ObjectSelector, applying
+/// validation to revision names. OID hex strings are always safe.
+///
+/// Returns "HEAD" when selector is None.
+///
+/// Usage:
+///   let revision = resolve_revision!(request.base);
+///   let revision = resolve_revision!(request.base, "main");
+#[macro_export]
+macro_rules! resolve_revision {
+    ($selector:expr) => {{
+        match $selector.and_then(|s| s.selector) {
+            Some($crate::pb::object_selector::Selector::Oid(oid)) => oid.hex,
+            Some($crate::pb::object_selector::Selector::Revision(name)) => {
+                $crate::sanitize::validate_revision(&name.revision)?;
+                name.revision
+            }
+            None => "HEAD".into(),
+        }
+    }};
+    ($selector:expr, $default:expr) => {{
+        match $selector.and_then(|s| s.selector) {
+            Some($crate::pb::object_selector::Selector::Oid(oid)) => oid.hex,
+            Some($crate::pb::object_selector::Selector::Revision(name)) => {
+                $crate::sanitize::validate_revision(&name.revision)?;
+                name.revision
+            }
+            None => ($default).into(),
+        }
+    }};
+}