Band Lineup 1.13.0: a photo per instrument, picked by the spot each person is in that week

DJ plays drums one week and sings the next; one photo can't fit both. A
person can now have a photo per instrument, named "Name - Instrument"
("DJ - Drums.jpg", "DJ - Vocals.jpg"), plus a plain "DJ.jpg" for
everything else. Sync reads the instrument family of the spot each person
lands in (its bracketed role, else their PCO position) and picks:

1. the photo picked by hand for them on that instrument;
2. a photo named for that instrument;
3. their everyday pick, else their best-named photo. A photo of them on
   another instrument still beats PCO's headshot.

Families keep the shorthands together: Vox/Vocals/Singer, Keys/Piano/Pad,
Drums/Perc, Bass, Guitar/Electric/Acoustic/Rhythm, Leader. A photo
dropped onto someone is remembered per person per instrument
("<id>|drums"), so a drum pick never overrides the vocal photo. A spot
naming several roles files under its most specific: Leader, then Vocals,
Drums, Keys, Bass, Guitar. Photo names from files now collapse the spaces
left by "Name - Instrument".

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

modules/band-lineup/matching.test.js

@@ -116,3 +116,28 @@ console.log('assignment:', JSON.stringify(out));
   assert.ok(!samePerson('Al Smith', 'Alex'), 'two-letter names never match by prefix');
   console.log('samePerson: all assertions passed ✓');
 }
+
+// --- a photo per instrument: "DJ - Drums", "DJ - Vocals", plain "DJ" for everything else ---
+{
+  const { bestLibraryMatch, photoParts, spotFamilies, roleFamilies, photoKey } = require('./matching');
+  // File names arrive with the dash turned to a space: "DJ - Drums.jpg" → "DJ Drums".
+  const lib = [{ id: 'e', name: 'DJ' }, { id: 'd', name: 'DJ Drums' }, { id: 'v', name: 'DJ Vocals' }, { id: 'k', name: 'Kevin Piano' }, { id: 'm', name: 'Mike Powell Leader' }];
+  const pick = (name, slot, pos) => { const e = bestLibraryMatch(name, lib, spotFamilies(slot, pos)); return e ? e.id : null; };
+  assert.strictEqual(pick('DJ McLean', '[DRUMS]', 'Drums'), 'd', 'on drums → drum photo');
+  assert.strictEqual(pick('DJ McLean', '[VOX 3] MIX 3', 'Vocalist'), 'v', 'on vocals → vocal photo');
+  assert.strictEqual(pick('DJ McLean', '[KEYS 2]', 'Keys 2'), 'e', 'on keys, no keys photo → everyday photo');
+  assert.strictEqual(pick('DJ McLean', 'STAGE MANAGER', 'Stage Manager'), 'e', 'no instrument → everyday photo');
+  assert.strictEqual(pick('Kevin Michel', '[KEYS 2]', 'Keys 2'), 'k', 'Piano and Keys are one family');
+  assert.strictEqual(pick('Kevin Michel', '[DRUMS]', 'Drums'), 'k', 'only photo is on piano → still his own photo, not PCO');
+  assert.strictEqual(pick('Mike Powell', '[LEADER, VOX 1, ACOUSTIC] MIX 1', '[Leader]'), 'm', 'full name + instrument');
+  assert.strictEqual(pick('Craig Strok', '[DRUMS]', 'Drums'), null, 'nobody else\'s instrument photo is borrowed');
+  assert.deepStrictEqual([...photoParts('DJ Drums action').roles], ['drums'], 'extra words after the instrument are ignored');
+  assert.strictEqual(photoParts('Joshua P').roles.size, 0, 'a plain name has no instrument');
+  assert.strictEqual(photoParts('Keys').person, 'keys', 'the first word is always the person');
+  assert.deepStrictEqual([...spotFamilies('[BASS] MIX 6', 'Guitar [Bass]')], ['bass'], 'the spot decides, not the position');
+  assert.deepStrictEqual([...roleFamilies('Guitar [Rhythm]')], ['guitar'], 'rhythm guitar is guitar');
+  assert.strictEqual(photoKey('dj', new Set(['drums'])), 'dj|drums');
+  assert.strictEqual(photoKey('dj', new Set()), 'dj');
+  assert.strictEqual(photoKey('mp', spotFamilies('[LEADER, VOX 1, ACOUSTIC] MIX 1', '[Leader]')), 'mp|leader', 'leader spot files under leader');
+  console.log('photos by instrument: all assertions passed ✓');
+}