The par2 prune gets 2 min per round (it held the merges back for hours); abandoned ranges past their end are finished

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/functional/leases.spec.ts

@@ -31,5 +31,12 @@ test.group('Leases', (group) => {
     // a1's worker went quiet: its lease is taken over (a2 alone counts).
     await db.from('ranges').where('id', a1).update({ heartbeat_at: new Date(Date.now() - 24 * 3600_000) })
     assert.equal(await leased(5), a1)
+
+    // Read to its end, its worker gone before finishing: done. One still reading, or quiet but not at its end, stays.
+    await db.from('ranges').where('id', a2).update({ next_id: 201, heartbeat_at: new Date(Date.now() - 24 * 3600_000) })
+    await db.from('ranges').where('id', b1).update({ next_id: 101 })
+    assert.equal(await Leases.finishAbandoned(), 1)
+    assert.equal((await db.from('ranges').where('id', a2).firstOrFail()).status, 'done')
+    assert.equal((await db.from('ranges').where('id', b1).firstOrFail()).status, 'leased')
   })
 })