Add antidote status cure item

docs/DATA_MODEL.md

@@ -302,7 +302,21 @@ Items start as static bonuses and consumable effects. Equipment leveling should
 
 Weapon `range` also uses `[min, max]`. When class and equipment both provide range, the runtime unit keeps the lowest minimum and highest maximum. Accessories use `kind: "accessory"` with an `accessory_type` checked against the class `equipment_slots.accessory` list; `war_drum` and `imperial_seal` are the first branch-choice accessory rewards. Current equipment inventory is stackable stock only; unique equipment instances, durability, and enhancement are planned later. `war_axe` is a stronger axe reward for the Warrior/Bandit weapon family.
 
-Consumables use `kind: "consumable"` with effect records. `heal_hp` restores HP and `heal_mp` restores MP to a valid target; `Bean` and `Wine` are the first examples. Item use consumes the acting unit's action and only commits to the save file on victory. Weapons, armor, and accessories can be granted through `rewards.items`; they are shown in inventory, can be equipped through the Equip menu before the unit moves or acts, and are not usable from the battle item menu.
+Consumables use `kind: "consumable"` with effect records. `heal_hp` restores HP, `heal_mp` restores MP, and `cure_status` removes matching damage-over-time status effects from a valid target; `Bean`, `Wine`, and `Antidote` are the first examples. Item use consumes the acting unit's action and only commits to the save file on victory. Weapons, armor, and accessories can be granted through `rewards.items`; they are shown in inventory, can be equipped through the Equip menu before the unit moves or acts, and are not usable from the battle item menu.
+
+```json
+{
+  "antidote": {
+    "name": "Antidote",
+    "kind": "consumable",
+    "target": "ally",
+    "range": [0, 1],
+    "uses": 1,
+    "effects": [{ "type": "cure_status", "status": "poison" }],
+    "price": 70
+  }
+}
+```
 
 Scenario `shop.items` controls which positive-price items appear in the current pre-battle shop. `shop.conditional_items` can append extra stock when saved campaign flags match. Entries can be plain item ids or objects with `id` and optional non-negative `stock`; `shop.stock` and conditional block `stock` objects can also set finite limits by item id. Items omitted from stock data are unlimited. Finite stock is tracked as per-scenario purchase counts in the campaign save, so buying an item decrements that scenario's remaining stock and manual checkpoint saves preserve it. Purchases spend campaign gold, increment the campaign inventory count, save immediately, and then refresh the battle inventory copy if a scenario briefing is already loaded. The shop can also sell unequipped inventory stock back for 50% of base `price`, saving immediately and refreshing the loaded battle inventory copy. Later campaign data should add broader unlock flags.
 
@@ -504,8 +518,8 @@ During a battle, item consumption and equipment swaps affect `BattleState.battle
 
 Physical attacks grant normal attack/counter EXP only on hit after the attack/counter exchange resolves. A missed physical attack or counter grants a small miss EXP value, while defeat bonuses still require the attack to hit and defeat the target.
 
-Before a battle starts, `BattleScene` can buy priced items through `CampaignState.try_buy_item()` and sell unequipped inventory through `CampaignState.try_sell_item()`. Successful shop transactions update campaign gold, inventory, and finite-stock purchase counts in the save file immediately, then call `BattleState.set_inventory_snapshot()` so the upcoming battle sees the new stock. Pre-battle Armory changes call `CampaignState.try_save_prebattle_loadout()`, which merges the currently deployed roster snapshot into the saved roster and saves the adjusted inventory in the same operation. Pre-battle Roster calls `BattleState.try_set_unit_deployed()` to toggle optional player units while enforcing required officers and sortie limits. Pre-battle Formation calls `BattleState.try_set_prebattle_formation()`, which can move a player unit to an open formation cell or swap two player units inside the formation area. Roster and Formation choices are battle setup state, so the manual checkpoint stores campaign progression and saved loadout state but not unsaved sortie or starting-cell edits. Matching `briefing.conditional_lines` and `shop.conditional_items` are merged while the scenario loads, before the briefing panel opens. `post_battle_dialogue` is rendered by the battle scene after victory and before rewards/choices are shown in the result panel. Post-battle choices call `CampaignState.try_apply_post_battle_choice()`, which saves selected flags and rolls back flags, gold, and inventory if the save write fails.
+Before a battle starts, `BattleScene` can buy priced items through `CampaignState.try_buy_item()` and sell unequipped inventory through `CampaignState.try_sell_item()`. Successful shop transactions update campaign gold, inventory, and finite-stock purchase counts in the save file immediately, then call `BattleState.set_inventory_snapshot()` so the upcoming battle sees the new stock. Pre-battle Armory changes call `CampaignState.try_save_prebattle_loadout()`, which merges the currently deployed roster snapshot into the saved roster and saves the adjusted inventory in the same operation. Pre-battle Roster calls `BattleState.try_set_unit_deployed()` to toggle optional player units while enforcing required officers and sortie limits. Pre-battle Formation calls `BattleState.try_set_prebattle_formation()`, which can move a player unit to an open formation cell or swap two player units inside the formation area. Roster and Formation choices are battle setup state, so the manual checkpoint stores campaign progression and saved loadout state but not unsaved sortie or starting-cell edits. Matching `briefing.conditional_lines` and `shop.conditional_items` are merged while the scenario loads, before the briefing panel opens. During battle, item previews can show HP/MP recovery and status cures, and no-effect item use is rejected without consuming stock. `post_battle_dialogue` is rendered by the battle scene after victory and before rewards/choices are shown in the result panel. Post-battle choices call `CampaignState.try_apply_post_battle_choice()`, which saves selected flags and rolls back flags, gold, and inventory if the save write fails.
 
 When every campaign scenario id is present in `completed_scenarios`, the battle scene shows a campaign completion panel. Starting a new campaign clears the automatic save file and resets `current_scenario_id` to `start_scenario`; the manual checkpoint is left alone until overwritten from the Save menu.
 
-Run `tools/validate_data.ps1` after data edits to check campaign paths, chapter ranges, map dimensions, terrain keys, class/officer/item/skill references, skill status effect shapes, item effect names and amounts, equipment slot compatibility including accessory types, promotion routes and promotion equipment compatibility, condition/event names, condition unit references, destination condition coordinates, campaign flag references, joined-officer gates, briefing line blocks, deployment ids, deployment bounds, impassable spawn cells, shop stock, roster rules, formation cells, post-battle dialogue, post-battle choices, and reward item ids.
+Run `tools/validate_data.ps1` after data edits to check campaign paths, chapter ranges, map dimensions, terrain keys, class/officer/item/skill references, skill status effect shapes, item effect names and cure statuses, equipment slot compatibility including accessory types, promotion routes and promotion equipment compatibility, condition/event names, condition unit references, destination condition coordinates, campaign flag references, joined-officer gates, briefing line blocks, deployment ids, deployment bounds, impassable spawn cells, shop stock, roster rules, formation cells, post-battle dialogue, post-battle choices, and reward item ids.