Identify queue items by commit hash, not id

migrations/20230806143356_queue.sql

@@ -1,6 +1,5 @@
 CREATE TABLE queue (
-    id       TEXT NOT NULL PRIMARY KEY,
-    hash     TEXT NOT NULL,
+    hash     TEXT NOT NULL PRIMARY KEY,
     date     TEXT NOT NULL,
     priority INT  NOT NULL DEFAULT 0,
     FOREIGN KEY (hash) REFERENCES commits (hash) ON DELETE CASCADE