Reproduced in the browser (notes i55-repro, an eliminated guest at the boss round): in the Final Assault fight
the watched boss field shows the leader (enemy_9013_acstmk at 10,3), but in the boss round's prep the
eliminated player saw its own empty normal board (camera 'prep', no leader), and a scout of a teammate was the
normal board too, while the players prepare on their half of the boss field with the leader standing there.
Match.prepFieldMeta: in a boss round's prep the scout is built on the boss field (kind 'boss', BOSS_RECT,
units through finalAssault.js bossFieldPlacement: rows − 7, the right half mirrored with RIGHT ↔ LEFT, the player's side;
nextEnemies keeps the leader's spawn tile); game.js frames it with the boss-field prep camera of that side,
which shows the leader (render/app.js leaderShown). With item 56 an eliminated viewer gets it at the round
start without a tap. After the fix the same run: guest field kind 'boss', camera bossPrep, leader shown.
Golden unchanged. Tests: test/match/feedback5-boss-prep-scout.test.js (new, 2). Docs: design/network.md,
design/client.md (§15).