feedback5 CB3: 乌尔比安's S3 moves only onto a tile of his own board — no longer behind the red gate of the one-helper 联防 map nor onto a boss field's other half (community report of 2026-10-06, item 27)

Official: PRTS 乌尔比安 S3 备注 ③ — the 【移动】 takes the anchor tile if it can be deployed on, else the tile one beyond, else
his own tile. Cause: "deployable" was any standable tile of the battle rect; UNITE_RECT holds both halves of the 联防 map, and
on escaped_single (the lone helper on the left half, the enemies out of the middle gate at col 10) an anchor that met no
enemy flew on to the right half, where no enemy walks, and he stood there for the whole skill. Now the landing must also
lie on his player's board: Battle.onOwnBoard(ps, r, c), the board region GEO.FIELD mapped onto the field (the hunk is
byte-identical to CB4's 219ab31, which uses it for the 突袭 landing, so the two merge cleanly).

Golden: 1 scenario — fields hidden-boss_9-solo: his first cast from (2,5) landed on (2,11), the solo boss field's right
half (checked instrumented); he now stays and the fight differs from there. Tests: test/sim/feedback5-ulpia-own-board.test.js
(4; the one-helper and the two-helper 联防 cases fail on the parent); test/sim/facing-invariance.test.js — its open field
has no boards, so its setup counts every tile as the player's own (the own-board rule is a board-position rule, like the
deployment order the scenario already avoids).

server/sim/battle/players.js

@@ -3,6 +3,7 @@
 // Installed on Battle.prototype by server/sim/Battle.js (a method container: never instantiated; `this` is the battle).
 
 import { COLS, BOSS_ROW_OFFSET } from '../constants.js';
+import { GEO } from '../../../shared/constants.js';
 import { Unit } from '../units.js';
 import { normDir, mirrorDir } from '../dir.js';
 import { SkillRuntime } from '../skills.js';
@@ -70,6 +71,29 @@ export class BattlePlayers {
   /** Board → field tile for a player (see header). */
   mapTile(ps, row, col, abs = false) {
     if (abs || ps.coords === 'field') return [row, col];
+    return this._boardTile(ps, row, col);
+  }
+
+  /**
+   * Whether field tile (r, c) lies on player `ps`'s own board: the board region GEO.FIELD (rows 9–12, cols 2–10, the
+   * tiles its pieces are deployed on) mapped onto this field — the 联防 right-hand helper's +8 columns, the boss field's
+   * rows 2–5, the mirrored right half of a pair (whatever coordinates the player's input uses). Never the hand / 临时
+   * 整备区 rows of a boss field (rows 0–1, inside BOSS_RECT) nor the other half of a 联防 or boss field. Automatic
+   * redeployments that must stay where the player could deploy read it (the 突袭 landing, bonds/addon/battle.js raidTile).
+   */
+  onOwnBoard(ps, r, c) {
+    if (!ps) return false;
+    let keys = ps._boardKeys;
+    if (!keys) {
+      keys = ps._boardKeys = new Set();
+      for (let br = GEO.FIELD.r0; br <= GEO.FIELD.r1; br++) {
+        for (let bc = GEO.FIELD.c0; bc <= GEO.FIELD.c1; bc++) { const [fr, fc] = this._boardTile(ps, br, bc); keys.add(fr * COLS + fc); }
+      }
+    }
+    return keys.has(r * COLS + c);
+  }
+
+  _boardTile(ps, row, col) {
     const bossLike = this.kind === 'boss' || this.kind === 'hidden';
     let r = row;
     if (ps.rowOffset != null) r = row + ps.rowOffset;