feat: add download management actions

README.md

@@ -120,7 +120,7 @@ jack day to day:
 
 - **Overview** — your configured servers and peers, and whether each one
   initialized cleanly.
-- **Downloads** — in-flight and finished grabs.
+- **Downloads** — inspect, cancel, retry, and delete in-flight or finished grabs.
 - **Peers** — add, edit, and remove the friends you consume from.
 - **Servers** — add, edit, and remove your Radarr/Sonarr connectors.
 
@@ -483,6 +483,16 @@ leak peer/server names and URLs to peers. They live on the management API (separ
 port, authenticated with the management key): `GET /config/servers`, `GET /config/peers`,
 `GET /overview`, and `GET /downloads`.
 
+Downloads are managed by their numeric record ID rather than their synthetic
+infohash, so separate grabs of the same release remain isolated:
+
+- `POST /downloads/:id/cancel` — stop an active transfer and preserve its `.part`
+  file for a later retry.
+- `POST /downloads/:id/retry` — repeat the last failed operation; transfers resume
+  from the partial file, while failed manual imports retry without downloading again.
+- `DELETE /downloads/:id` — cancel any active work, remove the history row, and
+  delete its unshared partial or completed artifacts.
+
 ## Running without Docker
 
 ```bash

apps/backend/drizzle/0010_calm_cyclops.sql

@@ -0,0 +1,8 @@
+ALTER TABLE `downloads` ADD `last_operation` text DEFAULT 'transfer' NOT NULL;--> statement-breakpoint
+ALTER TABLE `downloads` ADD `operation_failed` integer DEFAULT false NOT NULL;--> statement-breakpoint
+UPDATE `downloads`
+SET `last_operation` = CASE
+  WHEN `completed_at` IS NOT NULL OR `status` IN ('import_queued', 'imported') THEN 'import'
+  ELSE 'transfer'
+END,
+`operation_failed` = CASE WHEN `status` = 'failed' THEN true ELSE false END;