Add poison damage over time tactics

docs/ARCHITECTURE.md

@@ -38,9 +38,9 @@
 4. Show scenario briefing with the campaign chapter header, battle header, objective summary, chapter overview, manual checkpoint menu, and optional pre-battle shop, Armory, Roster, and Formation setup.
 5. Player selects a unit.
 6. Briefing completion dispatches battle-begin events, including opening dialogue.
-7. Unit moves, attacks, chooses a tactic or consumable item from the side menu, changes equipment, counters, gains EXP, levels up, promotes at class thresholds, or waits. Tactic buttons show MP cost, kind, range, and power, support, or debuff effect. Physical attacks roll hit chance from unit agility and target terrain avoid; misses give reduced EXP. The scene plays placeholder SFX, a short movement slide, low-HP warning rings, hover target preview badges, and floating combat text for core action and UI feedback.
+7. Unit moves, attacks, chooses a tactic or consumable item from the side menu, changes equipment, counters, gains EXP, levels up, promotes at class thresholds, or waits. Tactic buttons show MP cost, kind, range, and power, support, debuff, or damage-over-time effect. Physical attacks roll hit chance from unit agility and target terrain avoid; misses give reduced EXP. The scene plays placeholder SFX, a short movement slide, low-HP warning rings, hover target preview badges, and floating combat text for core action and UI feedback.
 8. Player ends turn.
-9. Enemy AI moves, attacks, and can cast damage or healing tactics through the same combat and skill resolvers.
+9. Enemy AI moves, attacks, and can cast damage, healing, support, debuff, or damage-over-time tactics through the same combat and skill resolvers.
 10. Battle checks scenario-defined defeat conditions first, including commander loss and turn limits, then victory conditions such as enemy defeat or reaching a marked destination tile.
 11. Turn-start and movement-triggered scenario events run as phases change or units enter marked cells, and may update objectives or deploy reinforcements.
 12. On first-time victory, `CampaignState` snapshots player progression and the battle inventory, applies rewards once, advances `current_scenario_id`, and writes `user://campaign_save.json`.
@@ -58,6 +58,6 @@ Joined officers gate whether `requires_joined` player deployments are loaded at
 
 Inventory and campaign flags are copied from `CampaignState` into `BattleState` when a scenario starts. The pre-battle Chapters overview reads `CampaignState` chapter progress and can load completed or current battles without mutating the save. The pre-battle Save menu can write the current campaign state to `user://campaign_manual_save.json`, and loading that checkpoint restores it into `user://campaign_save.json` before re-entering the same pending-choice, completion, or current-briefing branch as startup. Pre-battle shop stock comes from the loaded scenario's `shop.items` list plus matching `shop.conditional_items` blocks, with optional finite limits from item entries or `stock` maps. Shop purchases and 50% sell-back are campaign transactions: they update saved gold, unequipped inventory, and finite-stock purchase counts immediately, write the save file, and refresh the already-loaded battle inventory before the player begins the battle. Pre-battle Armory equipment changes use the same equipment rules as battle HUD equipment changes, then immediately save merged roster equipment/stat snapshots and inventory stock. Pre-battle Roster uses scenario `roster.max_units`, `roster.required_officers`, and `roster.required_units` to mark optional player deployments as sortie or reserve; reserve units remain in the candidate list but are excluded from board occupancy, drawing, selection, AI targeting, and living-unit victory checks. Non-controllable player units can act as protected escort targets: enemies can attack them and conditions can reference them, but they are skipped by player selection, Armory, Formation, counterattacks, and campaign roster progression snapshots when `persist_progression` is false. Scenario `ai_target_priority` nudges enemy movement and damage-skill scoring toward important targets such as envoys without overriding defeat bonuses or range checks. Pre-battle Formation uses the loaded scenario's `formation.cells` and only mutates current battle unit positions before battle-begin events fire. Destination victory cells from `unit_reaches_tile` conditions are exposed to the scene for objective overlays and tile info. Movement-triggered `unit_reaches_tile` events receive the unit that just moved, so ambushes fire on entry rather than from units already standing on a marker. Briefing data can append matching `briefing.conditional_lines`, and scenario events can use `when.campaign_flags` to branch dialogue, objective changes, and reinforcements from saved campaign choices. Consumable use can restore HP or MP, and in-battle item use plus equipment swaps mutate only the battle copy until victory; defeats and restarts do not spend saved items or preserve in-battle gear changes. Post-battle choices write campaign `flags` only after the result-panel button is pressed; if the player reloads after rewards are saved but before selecting, the pending scenario id restores the victory choice panel without replaying rewards. The next battle button stays locked until the campaign choice save succeeds. Equipment rewards share the same `item_id -> count` inventory stock, cover weapon, armor, and accessory slots, can be equipped from the side HUD before the selected unit moves or acts, and do not appear in the consumable action menu. Already completed scenarios can be replayed without granting duplicate rewards, choices, replay inventory consumption, save writes, current-scenario advancement, or finite-stock purchases; pre-battle Shop, Armory, Roster, Formation, and Save are disabled on completed-scenario replays to avoid side effects.
 
-The battle scene owns presentation feedback: briefing and result states use menu BGM, briefing headers combine `CampaignState` chapter ranges, campaign order, and title data with `BattleState` briefing and objective text, active battles use battle BGM, dialogue lines can show optional portrait textures or speaker-initial fallback panels and can place the portrait on the left or right side of the dialogue panel, board units render low-HP warning rings and HP bar color states from battle state fields, hover previews are rendered as target badges from existing `BattleState` forecast APIs, log/result hooks trigger placeholder SFX, support and debuff effects use distinct floating feedback colors, `BattleState.unit_motion_requested` asks the scene to interpolate a unit's draw position during movement, and `BattleState.combat_feedback_requested` asks the scene to draw transient floating combat text without changing battle rules.
+The battle scene owns presentation feedback: briefing and result states use menu BGM, briefing headers combine `CampaignState` chapter ranges, campaign order, and title data with `BattleState` briefing and objective text, active battles use battle BGM, dialogue lines can show optional portrait textures or speaker-initial fallback panels and can place the portrait on the left or right side of the dialogue panel, board units render low-HP warning rings and HP bar color states from battle state fields, hover previews are rendered as target badges from existing `BattleState` forecast APIs, log/result hooks trigger placeholder SFX, support, debuff, and poison effects use distinct floating feedback colors, `BattleState.unit_motion_requested` asks the scene to interpolate a unit's draw position during movement, and `BattleState.combat_feedback_requested` asks the scene to draw transient floating combat text without changing battle rules.
 
 The `New Campaign` button clears `user://campaign_save.json`, resets campaign state to the first scenario, and reloads the opening briefing.

docs/DATA_MODEL.md

@@ -226,7 +226,7 @@ Classes provide movement, min/max attack range, skill access, growth grades, cla
 
 ## Skills
 
-Skills define MP tactics. A class, officer, or scenario deployment can add skill ids to the runtime unit. `range` is `[min, max]` in Manhattan distance and can use `0` as the minimum for self-targeting support skills. Skill `kind` can be `damage`, `heal`, or `support`. Enemy AI can use `damage` and `heal` skills when it has enough MP.
+Skills define MP tactics. A class, officer, or scenario deployment can add skill ids to the runtime unit. `range` is `[min, max]` in Manhattan distance and can use `0` as the minimum for self-targeting support skills. Skill `kind` can be `damage`, `heal`, or `support`. Enemy AI can use damage, healing, support, debuff, and damage-over-time skills when it has enough MP.
 
 ```json
 {
@@ -242,9 +242,26 @@ Skills define MP tactics. A class, officer, or scenario deployment can add skill
 }
 ```
 
-Support skills use an `effects` array. The first supported effect is `stat_bonus`, with `stat` in `atk`, `def`, `int`, or `agi`, a non-zero `amount`, and positive `duration_turns`. Positive amounts are buffs and negative amounts are debuffs; both are battle-only and expire when the target's team begins enough future phases.
+Support skills use an `effects` array. `stat_bonus` uses `stat` in `atk`, `def`, `int`, or `agi`, a non-zero `amount`, and positive `duration_turns`. Positive amounts are buffs and negative amounts are debuffs; both are battle-only and expire when the target's team begins enough future phases. `damage_over_time` uses a stable `status`, positive `amount`, and positive `duration_turns`; it ticks at the start of the target team's phase before expiration and can defeat units without awarding delayed defeat EXP.
 
-The current single-target tactic set includes `spark`, `fire_tactic`, `blaze`, `mend`, `great_mend`, `guard_order`, `rally_order`, and `disrupt_order`. Hero and strategist classes get low-cost Spark alongside Fire/Mend, ally orders, and the first enemy debuff, promoted command/advisor classes add Great Mend, and late scenario deployments can add stronger pressure skills such as Blaze without changing their base class.
+```json
+{
+  "poison_mist": {
+    "name": "Poison Mist",
+    "kind": "support",
+    "target": "enemy",
+    "mp_cost": 6,
+    "range": [1, 3],
+    "power": 0,
+    "stat": "int",
+    "effects": [
+      { "type": "damage_over_time", "status": "poison", "amount": 4, "duration_turns": 2 }
+    ]
+  }
+}
+```
+
+The current single-target tactic set includes `spark`, `fire_tactic`, `blaze`, `mend`, `great_mend`, `guard_order`, `rally_order`, `disrupt_order`, and `poison_mist`. Hero classes get low-cost Spark alongside Fire/Mend and ally orders, strategist classes also get Poison Mist, promoted command/advisor classes add Great Mend, and late scenario deployments can add stronger pressure skills such as Blaze without changing their base class.
 
 ## Terrain
 
@@ -475,7 +492,7 @@ Event-spawned units use the same compact deployment shape as scenario starting u
 
 ## Current Implementation
 
-`scripts/core/data_catalog.gd` reads definition files once and `BattleState._apply_battle_data()` accepts either legacy `units` or catalog-backed `deployments`. Runtime units now carry `min_range`, `range`, `skills`, `exp`, `growth`, `growth_bonus`, and battle-only `status_effects` so the battle resolver can handle counterattacks, MP tactics, support buffs, enemy debuffs, EXP, level-ups, and enemy tactic AI without changing scenario files.
+`scripts/core/data_catalog.gd` reads definition files once and `BattleState._apply_battle_data()` accepts either legacy `units` or catalog-backed `deployments`. Runtime units now carry `min_range`, `range`, `skills`, `exp`, `growth`, `growth_bonus`, and battle-only `status_effects` so the battle resolver can handle counterattacks, MP tactics, support buffs, enemy debuffs, damage-over-time statuses, EXP, level-ups, and enemy tactic AI without changing scenario files.
 
 `scripts/core/campaign_state.gd` writes `user://campaign_save.json` with `save_version`, completed scenarios, gold, inventory counts, joined officers, pending post-battle choice scenario id, applied post-battle choice ids, campaign flags, per-scenario shop purchase counts, and player roster progression. The same snapshot can be copied to the one-slot manual checkpoint at `user://campaign_manual_save.json` from the pre-battle Save menu. Loading that checkpoint restores it into the active automatic save and then reloads the pending choice panel, campaign completion state, or current scenario briefing. Roster snapshots include level, EXP, stats, class id/name, class-derived movement/range/growth fields, skills, and equipment. Rewards, joined/left officers, and post-battle choices are guarded by completed scenario id so restarting a finished battle does not duplicate gold, items, membership changes, branch decisions, or finite shop purchases. On load, completed-scenario officer join/leave transitions are reconciled without replaying gold or item rewards, which lets new officer rewards added to older completed scenarios become available to existing saves.
 
@@ -491,4 +508,4 @@ Before a battle starts, `BattleScene` can buy priced items through `CampaignStat
 
 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, 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 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.

docs/GODOT_4_6_MIGRATION.md

@@ -46,6 +46,7 @@ powershell -NoProfile -ExecutionPolicy Bypass -File tools\check_godot46_readines
 - Finite-stock Shop entries show remaining counts and disable once sold out.
 - Manual checkpoint save/load restores the expected current briefing without script errors.
 - A player unit can move, attack, wait, use a tactic, use an item, and equip compatible gear.
+- Poison Mist applies poison, poison ticks at the target team's phase start, and poison defeat immediately ends the battle when it satisfies a victory or defeat condition.
 - Enemy turn advances and AI acts.
 - Victory and defeat panels still appear.
 - Post-battle dialogue and post-battle choices still block progression until a choice is saved.

docs/ROADMAP.md

@@ -32,9 +32,9 @@
 - Weapon, armor, and accessory slots. Basic stat bonuses exist.
 - Equipment rewards can be stored, displayed, and swapped from the battle HUD.
 - Terrain movement, defense, and avoid modifiers affect combat.
-- Skills, tactics, and MP. Multiple single-target damage/heal tactics, ally support buffs, enemy debuffs, a skill list menu with range/effect hints, and enemy tactic AI exist.
+- Skills, tactics, and MP. Multiple single-target damage/heal tactics, ally support buffs, enemy debuffs, poison damage-over-time, a skill list menu with range/effect hints, and enemy tactic AI exist.
 - Consumable item use. Basic global inventory, Bean HP recovery, Wine MP recovery, item menu, preview, and target overlay exist.
-- Counterattacks exist. Battle-only support and debuff status effects exist; richer ailment/status families are still planned.
+- Counterattacks exist. Battle-only support, debuff, and first damage-over-time status effects exist; richer ailment/status families are still planned.
 - Battle EXP, level-ups, class promotion, and campaign roster persistence exist.
 
 ## Milestone 3: Scenario Layer
@@ -133,7 +133,7 @@
 
 - Portrait pipeline. Officer definitions can provide default portrait paths, dialogue lines can override them, and missing art falls back to speaker initials.
 - Unit sprites and animations. Board movement now has a short slide animation, and board units show low-HP warning rings.
-- Battle effects. First floating combat text now covers damage, recovery, misses, support effects, level-ups, and promotions. Hover target preview badges summarize attacks, tactics, and items.
+- Battle effects. First floating combat text now covers damage, recovery, misses, support effects, poison ticks, level-ups, and promotions. Hover target preview badges summarize attacks, tactics, and items.
 - Music and sound. Basic placeholder BGM and SFX now play for menus, battle flow, unit actions, tactics, items, and result states.
 - Chapter UI and visual novel scenes. Pre-battle briefing now uses campaign chapter ranges for chapter-aware numbering, has a chapter progress/replay overview, and dialogue lines can choose left or right portrait placement.