feedback5 CB5: an eliminated player (and a spectator seat) follows a player through every phase reset — the one it last watched, else the first player still in — instead of being sent back to its own empty board each round (community report of 2026-10-06, item 56; the idea of PR #189)

Official: research 09 §3.1 — after elimination the client keeps observing (self_dead_dialog KEEP_WATCH,
DeadAutoObDn { obIndex, state, preparation }, FindFirstAvailObTarget). Until 0.2.0 every phase reset cleared
an eliminated player's watch: in 回合开始 / 机变 / 休整期 it saw its own empty board, in battle the first field.

Server (server/match/match/watch.js): Match.watchPref (viewer → the player of its last manual g.watch: a prep
scout, a single-player field, or the new optional g.watch playerId on a shared 联防 / boss pair field — PR
#189's review point); _watchTargetOf = that player while still in, else the first player still in (seat
order, AI seats included); startRound scouts its board (_followScout, kept through 机变 and 休整期), both
combat modes and the boss fields start on its field, a resync / a spectator joining in prep gets the board,
a followed player who quits hands over at once. Client: the screen adopts the pushed board like a 前往查看 tap
(battle/observe.js followedScout; the stale-field fix of PR #189), keeps it through the prep phases (no camera
flight home and back), a spectator no longer asks for the first player itself; g.watch sends the tapped row.
Overlap with PR #189 (not merged): the same preference chain; differences — the fallback includes AI seats
(a lone human with AI teammates had nobody to follow), shared fields record the tapped playerId.

Golden unchanged. Tests: test/match/feedback5-watch-follow.test.js (new, 9), spectator.test.js updated (the
spectator follows the player it scouted). Docs: design/network.md, PLAYING.md.

server/match/Match.js

@@ -64,7 +64,9 @@
 // addSpectator(id)          (optional for the platform) A spectator seat joined during the match, came back or asked
 //                           for a resync: register it (idempotent) and resend what an ELIMINATED player watching sees —
 //                           m.public and, while a battle runs, the b.start (watch) of the field it watches (default: the
-//                           first field; server-run mode: m.field + b.snap), or m.result once ended. A spectator gets
+//                           field of the player it follows — the one it last watched, else the first player still in;
+//                           server-run mode: m.field + b.snap), in a prep phase that player's board (m.field prep), or
+//                           m.result once ended. A spectator gets
 //                           every broadcast through the platform, never an m.private / m.toast / m.unitStats, is never
 //                           a field's player or authority, and is shown fields like an eliminated player in every phase.
 //                           handle(id, msg) answers only its 'g.watch' (anything else → SPECTATOR; the platform routes
@@ -358,6 +360,12 @@ export class Match {
     this.runner = null;
     /** playerId → fieldId */
     this.watchers = new Map();
+    /**
+     * Watch preference (community report of 2026-10-06, item 56; the idea of PR #189): viewer playerId → the player it
+     * last chose to watch with a manual g.watch. Every phase reset starts an eliminated human or a spectator seat on that
+     * player again (its prep board, its battle field) — else the first player still in — instead of its own empty board.
+     */
+    this.watchPref = new Map();
     this.lastResults = new Map();
     this.unitePlan = null;
     /** server-run 联防: the leakers' counts last published (_uniteTick) */