feat: add runtime policy and observability

src/worker/mod.rs

@@ -1,6 +1,7 @@
 use crate::error::{AppError, ErrorCode};
 use crate::services::billing;
 use crate::services::compress;
+use crate::services::metrics;
 use crate::services::quota;
 use crate::services::storage;
 use crate::state::AppState;
@@ -15,9 +16,9 @@ use tokio::sync::Semaphore;
 use tokio::task::JoinSet;
 use uuid::Uuid;
 
-const STREAM_KEY: &str = "stream:compress_jobs";
-const GROUP_NAME: &str = "compress_workers";
-const DEAD_STREAM_KEY: &str = "stream:compress_jobs:dead";
+const STREAM_KEY: &str = metrics::QUEUE_STREAM_KEY;
+const GROUP_NAME: &str = metrics::QUEUE_GROUP_NAME;
+const DEAD_STREAM_KEY: &str = metrics::DEAD_STREAM_KEY;
 const MAX_DELIVERIES: usize = 3;
 const STALE_MESSAGE_IDLE_MS: usize = 5 * 60 * 1000;
 
@@ -136,6 +137,7 @@ async fn handle_message(
                 write_dead_letter(conn, &msg.id, task_id, deliveries, &err).await?;
                 mark_task_dead_letter(state, task_id, &err.message).await?;
                 ack_message(conn, &msg.id).await?;
+                metrics::record_dead_letter(state);
                 tracing::error!(
                     task_id = %task_id,
                     deliveries,