feat(api): update rust deps, move /private/meta endpoint to rust-api

lib/libpk/src/db/repository/stats.rs

@@ -0,0 +1,13 @@
+pub async fn get_stats(pool: &sqlx::postgres::PgPool) -> anyhow::Result<Counts> {
+    let counts: Counts = sqlx::query_as("select * from info").fetch_one(pool).await?;
+    Ok(counts)
+}
+
+#[derive(serde::Serialize, sqlx::FromRow)]
+pub struct Counts {
+    pub system_count: i64,
+    pub member_count: i64,
+    pub group_count: i64,
+    pub switch_count: i64,
+    pub message_count: i64,
+}