feat(service): expand service layer with new domain operations

- Add IM service modules: audit, channel roles, custom emojis, forum
  tags, integrations, invitations, repo links, slash commands, stages,
  voice, webhooks
- Add PR service modules: review requests, templates
- Add repo service modules: contributors, release assets, git extras
  (archive, branch rename, commit extras, diff/merge, tag, tree)
- Add user service: social (follow/block)
- Add internal auth service
- Update existing service modules with expanded functionality
- Remove deleted IM modules: articles, delivery trace, drafts,
  follows, messages, polls, presence, reactions, threads

service/repo/git/branch_rename.rs

@@ -0,0 +1,31 @@
+use crate::error::AppError;
+use crate::service::RepoService;
+use crate::session::Session;
+
+impl RepoService {
+    pub async fn git_rename_branch(
+        &self,
+        ctx: &Session,
+        wk_name: &str,
+        repo_name: &str,
+        old_name: &str,
+        new_name: &str,
+    ) -> Result<crate::pb::repo::Branch, AppError> {
+        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
+        let repo = self.resolve_repo(wk_name, repo_name).await?;
+        self.ensure_repo_role_at_least(user_uid, &repo, crate::models::common::Role::Admin)
+            .await?;
+        let ws = self.resolve_workspace(wk_name).await?;
+        let header = self.repo_header(&repo, &ws);
+        let mut svc = self.git_client(&repo)?.branch;
+        let resp = svc
+            .rename_branch(tonic::Request::new(crate::pb::repo::RenameBranchRequest {
+                repository: Some(header),
+                old_name: old_name.to_string(),
+                new_name: new_name.to_string(),
+            }))
+            .await
+            .map_err(|e| AppError::InternalServerError(e.to_string()))?;
+        Ok(resp.into_inner())
+    }
+}