fix: include Vulpisfoglia Hunt addition on first damage

docs/SIM.md

@@ -1065,6 +1065,11 @@ has the generic spec. Summons: `battle.tokenDef(tokenId, unit)` / `battle.spawnT
 (token skill of that slot: `variants[owner].bySkill[i]`, module attributes: `.byModule[id]`). Coverage of the selectable
 skills: `node tools/kit-coverage.mjs --missing [--tier N] [--strict]`.
 
+忍冬's 追凶 records the per-enemy start time and applies its arts addition in the same `damaged` callback,
+including the first instance (PRTS talent remarks; DESIGN §29.15). It does not refresh the ten-second window on
+repeated hits. Its `vulpisHunt` / `addition` tags and re-entrancy guard prevent the rider from feeding itself.
+`test/content/vulpis-first-hit.test.js` checks actual HP loss and damage events with naturally ready skills.
+
 Timed deployment kits: 宴 S2 uses `bb.duration` and skill ATK mods, loses current HP once on landing, and converts normal
 physical attacks to arts only while S2 is active; S1 has no such conversion. 斯卡蒂 S2 uses its own record's
 `s.bb.duration` / `s.bb.atk`; DRE-Y revival in place does not restart it. 野鬃 S1 uses its record's `duration` /

docs/design/engine.md

@@ -172,6 +172,8 @@ Profession traits (default behaviours implemented once in the engine, keyed by `
 Each domain file `server/sim/content/{tokens,bonds,garrisons,items,bands,enemies,bosses,devices,choices}.js` exports `install(battle)` (battle side; called once per Battle by `content/index.js → installContent`) and `registerMeta(registry)` (prep side; called once at server boot by `match/effectsMeta.js`, API documented in `docs/META.md`). Kits live one per file in `content/kits/ops/` (`export default { [baseChessId]: (bb, chess, def) => Kit }`), listed in `content/kits/index.js` (guide: `content/kits/README.md`). Content must be **data-driven from blackboards** (numbers never hard-coded when a blackboard key exists). Every effect gets at least one unit test in `test/content/*.test.js` using the `test/helpers/battleHarness.js` harness (provided by sim-core).
 
 - kits: all 112 visible chess + hidden ones used by effects (盟约·辅助干员), default skill + talents + trait specifics; tokens. The 72 non-collaboration 6★ DIY operators include 克莱门莎 (§28.1); her launch-day provisional mechanics are local to her kit. 黍 GUA-Y and 乌尔比安 CRU-Y follow the generated module blackboards and existing module-level rules (§28.2).
+  忍冬's 追凶 adds arts damage on the first qualifying instance too; the per-enemy window starts on that instance,
+  and repeated hits do not extend it. The addition keeps its own tag and re-entrancy guard (§29.15).
   克莱门莎 S2 removes dead, hidden, self-bound / teleport-immune and unreachable passengers before checking new
   boarding in the same tick. Each released passenger returns its current weight to the cabin's remaining budget
   and frees its slot (§28.27); neither corpses nor failed carries reserve capacity.

docs/history/0.2.4.md

@@ -274,3 +274,22 @@ enemy: picking emitted a unit click with no definition, instead of the tile clic
 engine-canvas regression retains the card/100 HP assertions and also covers another field refresh, live HP loss and
 closing the card when the crate is destroyed. Device metadata supplied by the new entry still wins; changing fields
 does not carry old devices across. Gameplay and allied targeting rules are unchanged.
+
+### 29.15 Vulpisfoglia's first Hunt instance
+
+[PRTS 忍冬](https://prts.wiki/w/忍冬), 追凶's remarks, includes the first damage instance in its arts addition.
+The mode's generated talent blackboard (`chess_char_3_18_a/b`, `atk_scale` 0.3, `interval` 10) supplies the numbers;
+no mode-specific first-hit exception was found. The old callback recorded the first timestamp and returned,
+skipping the addition on every new enemy. Kit hooks are installed before initial deployment, so this was not a
+delayed stat or talent installation.
+
+The callback now records the timestamp and continues to the existing addition path on that same instance.
+The fixed window, damage tags, dodge settings and recursion guard retain their previous behavior; skills,
+modules and other operators are unchanged. Full-content controlled-enemy tests cover ordinary first hits in both
+forms and all selectable modules/skills, first skill damage from S1–S3, per-enemy timing and actual HP/event totals.
+The existing HP-loss conversion regression now expects one rider on every attack, including the first.
+
+The intended golden moves are `roster-007/009/026/039`, `bond-soloShip-low`, `bond-yanShip-low`,
+`coop2-NORMAL-3`, `coop4-ABYSS-7` and `coop2-NORMAL-5-coverage-diy`: the extra first instance changes damage,
+kills and downstream battle/match choices in scenarios that field Vulpisfoglia. Fields, stand-ins and DIY
+scenarios retain their digests.