Identity: hashed stems under a tag, numbered volumes, scene tracks

From the top-100 groups:
- A hashed stem under text without a counter is the upload ("Seit 1753
  Tagen - usenet4ever.info - "055631a1_b6c820bc_…-u4e.part01.rar""): the
  day's uploads were one release of 3,747 files.
- A numbered volume as the extension, within the [i/M] total ("(????)
  [0659/2195] - "DN.VPL PCK.1508"", "TKY.ASN PCK.691."): keyed without it.
- Scene tracks under a bare counter ("[06/14] - "02-repiet_-_dont_think_
  twice_(extended_mix).mp3""): the artist's album bounded by the total.

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

tests/unit/release/identity.spec.ts

@@ -276,6 +276,22 @@ test.group('release / par2 names', () => {
     assert.notEqual(vlad('185', 77, 'P8250001.JPG').key, vlad('234', 77, 'P5300085.JPG').key)
   })
 
+  test('hashed stems under a tag, volume numbers as extensions, scene tracks under a bare counter', ({ assert }) => {
+    const id = (subject: string, name: string) => releaseIdentity({ poster: 'p', subject, name, weak: false })!
+    const u4e = (n: string) => id(`Seit 1753 Tagen - usenet4ever.info - "${n}" yEnc`, n)
+    assert.equal(u4e('055631a1_b6c820bc_a856086c_85112a5-u4e.part01.rar').key, u4e('055631a1_b6c820bc_a856086c_85112a5-u4e.par2').key)
+    assert.notEqual(u4e('055631a1_b6c820bc_a856086c_85112a5-u4e.part01.rar').key, u4e('4cc7c4c6_d3c2fecf_0bff51d6_d10df86-u4e.part01.rar').key)
+    const pck = (i: string, n: string) => id(`(????) [${i}/2195] - "${n}" yEnc`, n)
+    assert.equal(pck('0659', 'DN.VPL PCK.1508').key, pck('0660', 'DN.VPL PCK.1509').key)
+    assert.equal(pck('0659', 'DN.VPL PCK.1508').name, 'DN.VPL PCK.1508')
+    const movie = (i: string, n: string) => id(`[${i}/30] - "${n}" yEnc`, n)
+    assert.notEqual(movie('01', 'Movie.2008').key, movie('02', 'Movie.2009').key)
+    const track = (i: string, n: string) => id(`[${i}/14] - "${n}" yEnc`, n)
+    assert.equal(track('06', '02-repiet_-_dont_think_twice_(extended_mix).mp3').key, track('07', '03-repiet_-_other_song.mp3').key)
+    assert.equal(track('06', '02-repiet_-_dont_think_twice_(extended_mix).mp3').name, 'repiet')
+    assert.equal(track('01', '01-2bm_mq-real_rap_(intro).mp3').name, '2bm_mq')
+  })
+
   test('an image without words around it is keyed by its set', ({ assert }) => {
     const id = (name: string, counter: string) => releaseIdentity({ poster: 'p', subject: `##[ "${name}" (${counter})`, name, weak: false })!
     assert.equal(id('diana-040-001.jpg', '01/68').key, id('diana-040-002.jpg', '02/68').key)