feedback6 R21A: a 突袭 member may land on a teammate's half when both halves of the field are taken — the two-helper 联防 field and the Final Assault / Hidden Core pair field (the owner's decision of 2026-10-07): Battle.onFieldBoard (onOwnBoard of any player of the battle) read by raidTile only; a lone 联防 helper's empty half, a solo boss field's other half and the hand / 临时整备区 rows stay closed, every other landing rule kept, 乌尔比安's S3 【移动】 keeps onOwnBoard; golden: 8 moved, each parting from the parent at a member's first landing on its teammate's half (checked tick by tick with the parent instrumented) — fields boss-boss_2 / 3 / 4 / 5 / 6-pair and hidden-boss_8 / 10-pair (the right player's 缄默德克萨斯 / 伊内丝 / 仇白 / 耀骑士临光 on the left player's half, 1–7 landings per battle, the first 0.3–39.8 s in), matches coop4-ABYSS-7 (round 6's two-helper 联防: ai_2's 斯卡蒂 on ai_1's half at 52 s; only ai_1 / ai_2 dmgDealt move, 8263 between them); unite-2 unchanged (its two landings stay on their own half)

Tests: test/sim/feedback5-raid-own-board.test.js — the pair field (the right player's member onto the left telin's board tile (2,3), the left player's onto the mirrored right (2,17), the hand rows closed) and the two-helper 联防 (each helper onto the other's half; 乌尔比安 beside a teammate stays on his own) fail on the parent; the solo boss field's hand rows and the lone helper unchanged.
Docs: docs/history/0.2.1.md (new, §26; §26.1 cites the owner's decision and PRTS 卫戍协议/帮助 §联防阶段), the DESIGN index row and versions line, a pointer from §25.18.1, docs/SIM.md (onFieldBoard; onOwnBoard now 乌尔比安's only).

test/sim/facing-invariance.test.js

@@ -117,8 +117,9 @@ test('战术家 援军 (伺夜): the tactical point is the tile in FRONT along t
 
 test('突袭 (raidShip): the landing tile beside the enemy turns with the member direction (equal candidates)', () => {
   // a diagonal-only range: two equally near landing tiles cover the enemy — the tie resolves in the member's frame. The
-  // enemy stands inside the player's own board (rows 9–12, cols 2–10): a member lands only there since 0.2.0
-  // (Battle.onOwnBoard, DESIGN §25.18), so all four diagonal tiles around (10, 6) are candidates in every direction
+  // enemy stands inside the player's own board (rows 9–12, cols 2–10): a member lands only on a board of its field since
+  // 0.2.0 (Battle.onFieldBoard — on a one-player field its own; DESIGN §25.18, §26.1), so all four diagonal tiles around
+  // (10, 6) are candidates in every direction
   const ER = 10, EC = 6;
   const rec = chessRec({ id: 'r_diag', bonds: ['raidShip'], profession: 'WARRIOR', skill: null, rangeGrid: [[1, 1], [-1, 1]] });
   const land = (dir) => {