feat(core): implement Git repository operations with gRPC services

- Add advertise_refs functionality for Git protocol communication
- Implement archive service with TAR/ZIP format support and streaming
- Create blame service for Git file annotation with line tracking
- Add branch management including create, delete, rename and compare operations
- Implement merge checking with conflict detection and fast-forward handling
- Add cherry-pick functionality for applying commits between branches
- Integrate gix library for Git repository operations and object handling
- Add comprehensive test suite covering all Git operations
- Implement proper error handling and repository validation
- Add pagination support for large result sets
- Create protobuf definitions for all Git operations and data structures
- Add build system for gRPC code generation and dependency management

build.rs

@@ -0,0 +1,51 @@
+use std::fs;
+use std::path::{Path, PathBuf};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let manifest_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR")?);
+    let proto_dir = manifest_dir.join("proto");
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR")?);
+
+    fs::create_dir_all(&out_dir)?;
+    clean_generated_files(&out_dir)?;
+
+    let protos = proto_files(&proto_dir)?;
+    for proto in &protos {
+        println!("cargo:rerun-if-changed={}", proto.display());
+    }
+    println!("cargo:rerun-if-changed={}", proto_dir.display());
+    println!("cargo:rerun-if-changed=build.rs");
+
+    tonic_build::configure()
+        .build_client(true)
+        .build_server(true)
+        .emit_rerun_if_changed(false)
+        .out_dir(&out_dir)
+        .compile_protos(&protos, &[proto_dir])?;
+
+    Ok(())
+}
+
+fn proto_files(proto_dir: &Path) -> Result<Vec<PathBuf>, Box<dyn std::error::Error>> {
+    let mut files = fs::read_dir(proto_dir)?
+        .map(|entry| entry.map(|entry| entry.path()))
+        .collect::<Result<Vec<_>, _>>()?;
+
+    files.retain(|path| path.extension().is_some_and(|ext| ext == "proto"));
+    files.sort();
+    Ok(files)
+}
+
+fn clean_generated_files(out_dir: &Path) -> Result<(), Box<dyn std::error::Error>> {
+    for entry in fs::read_dir(out_dir)? {
+        let path = entry?.path();
+        let is_generated_rs = path.extension().is_some_and(|ext| ext == "rs")
+            && path.file_name().is_some_and(|name| name != "mod.rs");
+
+        if is_generated_rs {
+            fs::remove_file(path)?;
+        }
+    }
+
+    Ok(())
+}