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/util.rs

@@ -1,5 +1,6 @@
 use crate::error::AppError;
 use crate::models::common::Role;
+use uuid::Uuid;
 
 pub fn merge_optional_text(next: Option<String>, current: Option<String>) -> Option<String> {
     next.map(|v| {
@@ -152,3 +153,12 @@ pub fn validate_password_strength(password: &str) -> Result<(), AppError> {
     }
     Ok(())
 }
+
+/// Build a `SET LOCAL app.current_user_id` statement with the UUID interpolated
+/// directly. PostgreSQL `SET` is a utility command that does not support
+/// parameterised `$1` placeholders through the extended query protocol.
+///
+/// Returns an `AssertSqlSafe` wrapper so sqlx 0.9 accepts the dynamic string.
+pub fn set_local_user_id(user_uid: Uuid) -> sqlx::AssertSqlSafe<String> {
+    sqlx::AssertSqlSafe(format!("SET LOCAL app.current_user_id = '{user_uid}'"))
+}