feat(server): configurable DB pool size via --db-max-connections/DB_MAX_CONNECTIONS (#2)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/server/src/lib.rs

@@ -15,7 +15,7 @@ use tokio::net::TcpListener;
 
 /// Connect dependencies from `config` and serve until shutdown.
 pub async fn run(config: Config) -> anyhow::Result<()> {
-    let db = Db::connect(&config.database_url)
+    let db = Db::connect(&config.database_url, config.db_max_connections)
         .await
         .context("connecting to the database")?;
 
@@ -136,7 +136,8 @@ pub async fn create_user(database_url: &str, email: &str, role: Role) -> anyhow:
         auth::hash_password(&password).map_err(|err| anyhow::anyhow!("hashing password: {err}"))?
     };
 
-    let db = Db::connect(database_url)
+    // CLI one-shot: a tiny pool is plenty.
+    let db = Db::connect(database_url, 2)
         .await
         .context("connecting to the database")?;