feat(api): extend commit and diff services with new functionality

- Add FindCommit, ListCommitsByOid, CommitIsAncestor RPCs to CommitService
- Add CheckObjectsExist, CommitsByMessage, GetCommitStats RPCs to CommitService
- Add LastCommitForPath, CountCommits, CountDivergingCommits RPCs to CommitService
- Add RawDiff, RawPatch, FindChangedPaths RPCs to DiffService
- Add FindMergeBase, WriteRef, SearchFilesByContent RPCs to RepositoryService
- Add SearchFilesByName, ObjectsSize, RepositorySize RPCs to RepositoryService
- Add FindLicense, OptimizeRepository, GetRawChanges RPCs to RepositoryService
- Add FetchRemote, CreateRepositoryFromURL RPCs to RepositoryService
- Implement server handlers for all new RPC methods
- Add new modules for commit counting, finding, and querying features
- Add new modules for diff changed paths and raw operations
- Add new modules for refs and remote operations
- Remove unnecessary comments from various source files
- Update proto definitions with new message types and service methods

repository/objects_size.rs

@@ -0,0 +1,93 @@
+use crate::bare::GitBare;
+use crate::error::GitResult;
+use crate::pb::*;
+
+impl GitBare {
+    /// Get sizes for a list of objects by OID.
+    pub fn objects_size(&self, request: ObjectsSizeRequest) -> GitResult<ObjectsSizeResponse> {
+        if request.oids.is_empty() {
+            return Ok(ObjectsSizeResponse::default());
+        }
+
+        let mut input = String::new();
+        for oid in &request.oids {
+            crate::sanitize::validate_revision(oid)?;
+            input.push_str(oid);
+            input.push('\n');
+        }
+
+        let mut child = std::process::Command::new("git")
+            .args([
+                "--git-dir",
+                &self.bare_dir.to_string_lossy(),
+                "cat-file",
+                "--batch-check=%(objectname) %(objectsize)",
+            ])
+            .stdin(std::process::Stdio::piped())
+            .stdout(std::process::Stdio::piped())
+            .stderr(std::process::Stdio::piped())
+            .spawn()
+            .map_err(|e| crate::error::GitError::CommandFailed {
+                status_code: None,
+                stderr: e.to_string(),
+            })?;
+
+        use std::io::Write;
+        if let Some(ref mut stdin) = child.stdin {
+            stdin.write_all(input.as_bytes()).map_err(|e| {
+                crate::error::GitError::CommandFailed {
+                    status_code: None,
+                    stderr: e.to_string(),
+                }
+            })?;
+        }
+
+        let output = child.wait_with_output().map_err(|e| {
+            crate::error::GitError::CommandFailed {
+                status_code: None,
+                stderr: e.to_string(),
+            }
+        })?;
+
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let mut sizes = Vec::new();
+
+        for line in stdout.lines() {
+            let parts: Vec<&str> = line.split_whitespace().collect();
+            if parts.len() >= 2 {
+                let oid = parts[0];
+                let found = parts.get(1).map_or(true, |&s| s != "missing");
+                let size = parts.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+                sizes.push(ObjectSize {
+                    oid: oid.to_string(),
+                    size,
+                    found,
+                });
+            }
+        }
+
+        Ok(ObjectsSizeResponse { sizes })
+    }
+
+    /// Get total repository size on disk.
+    pub fn repository_size(&self) -> GitResult<RepositorySizeResponse> {
+        let output = std::process::Command::new("du")
+            .args(["-sb", &self.bare_dir.to_string_lossy()])
+            .stdout(std::process::Stdio::piped())
+            .stderr(std::process::Stdio::piped())
+            .output()
+            .map_err(|e| crate::error::GitError::CommandFailed {
+                status_code: None,
+                stderr: e.to_string(),
+            })?;
+
+        let stdout = String::from_utf8_lossy(&output.stdout);
+        let size = stdout
+            .split_whitespace()
+            .next()
+            .and_then(|s| s.parse().ok())
+            .unwrap_or(0);
+
+        Ok(RepositorySizeResponse { size_bytes: size })
+    }
+}