feat(occupation): P15 补齐货郎/书生各 2 条每日任务模板 + 既有事件通道信号桥（Kernel 纯函数 TDD）

- TaskTemplateId 扩出 BuyGoods(收货)/Resell(转卖)/ObserveNotes(观察记事)/ReasonDebate(论理)，
  taskPoolOf 货郎=[收货,转卖]、书生=[观察记事,论理]，四职业池均非空。
- TaskSignal 增 Purchased(玩家买入)/Observed(观察)，satisfiesCompletion 给出四模板完成判定；
  新增 occupationSeedOf/refreshToday（跨日才重生成，同日含 Done/Failed 终态保留）。
- signalOfInteraction/advanceTask：仅 playerId 发起的 DialogueEvent/TradeEvent 产生信号，
  NPC 互动不派任务；Offered 须先 acceptTask，终态不可复活。WorldSave 模板 token 双向同步。
- 测试 83 全绿（新增 6：池非空、货郎书生逐日池内确定、模板中文名、完成信号正负、
  事件桥含玩家买/卖与 NPC 忽略、既有 DialogueEvent→accept→Done 全链路、refreshToday 逐日）。
- 不动 Sim.step 数值路径；旧档 v3 模板 token 仅新增合法值，未知模板仍拒绝。

1 files changed, 55 insertions, 6 deletions

diff --git a/src/LivingVillage.Kernel/Occupation.fs b/src/LivingVillage.Kernel/Occupation.fs
index 5c75c81..2168c4e 100644
--- a/src/LivingVillage.Kernel/Occupation.fs
+++ b/src/LivingVillage.Kernel/Occupation.fs
@@ -51,7 +51,8 @@ module Occupation =
         | Done
         | Failed
 
-    /// 首期任务池 = 农夫3（送粮/帮工/翻土）+ 渔夫3（夜捕/卖渔/询价），design §3 表。
+    /// 首期任务池 = 农夫3（送粮/帮工/翻土）+ 渔夫3（夜捕/卖渔/询价）
+    /// + P15 补齐货郎2（收货/转卖）+ 书生2（观察记事/论理），design §3 表。
     type TaskTemplateId =
         | DeliverGrain
         | HelpWork
@@ -59,6 +60,10 @@ module Occupation =
         | NightCatch
         | SellFish
         | MarketInquiry
+        | BuyGoods
+        | Resell
+        | ObserveNotes
+        | ReasonDebate
 
     let taskNameOf (template: TaskTemplateId) : string =
         match template with
@@ -68,14 +73,26 @@ module Occupation =
         | NightCatch -> "夜捕"
         | SellFish -> "卖渔"
         | MarketInquiry -> "询价"
+        | BuyGoods -> "收货"
+        | Resell -> "转卖"
+        | ObserveNotes -> "观察记事"
+        | ReasonDebate -> "论理"
 
-    /// 货郎/书生模板留后续单，当前为空池 → 不生成每日任务。
     let taskPoolOf (kind: Kind) : TaskTemplateId list =
         match kind with
         | Farmer -> [ DeliverGrain; HelpWork; TillSoil ]
         | Fisher -> [ NightCatch; SellFish; MarketInquiry ]
-        | Peddler
-        | Scholar -> []
+        | Peddler -> [ BuyGoods; Resell ]
+        | Scholar -> [ ObserveNotes; ReasonDebate ]
+
+    /// 每职业任务流种子：与世界 seed 异或后驱动 taskHash，使四职业的每日序列互不相同。
+    /// 纯常量（splitmix 同源），禁 System.Random。
+    let occupationSeedOf (kind: Kind) : uint64 =
+        match kind with
+        | Farmer -> 0x1111111111111111UL
+        | Fisher -> 0x2222222222222222UL
+        | Peddler -> 0x3333333333333333UL
+        | Scholar -> 0x4444444444444444UL
 
     type DailyTask =
         { TemplateId: TaskTemplateId
@@ -87,12 +104,15 @@ module Occupation =
 
     /// 完成判定信号（design §3：走既有事件通道）。
     /// Dialogued 来自 DialogueEvent（chooseDialogue）；Traded 来自 TradeEvent，
-    /// 字段序 = 卖方/物品/数量（玩家递出即 seller = playerId）；ArrivedAt 为到达瓦片；
+    /// 字段序 = 卖方/物品/数量（玩家递出即 seller = playerId）；Purchased = 玩家买入
+    /// （TradeEvent 中 playerId 为 buyer）；ArrivedAt 为到达瓦片；Observed 为观察面板；
     /// NightAtWater 由调用方把 isNight + 水边判定折叠后喂入。Sim.step 零感知。
     type TaskSignal =
         | Dialogued of Sim.NpcId
         | Traded of Sim.NpcId * Sim.ItemKind * int
+        | Purchased of Sim.ItemKind * int
         | ArrivedAt of int * int
+        | Observed
         | NightAtWater
 
     /// TargetNpc/TargetTile 为 None 时视为通配（指定目标由后续 Desktop 接线单落地）。
@@ -110,6 +130,10 @@ module Occupation =
         | NightCatch, NightAtWater -> true
         | SellFish, Traded (seller, item, quantity) -> seller = Sim.playerId && item = Sim.Fish && quantity >= 1
         | MarketInquiry, Dialogued _ -> true
+        | BuyGoods, Purchased (_, quantity) -> quantity >= 1
+        | Resell, Traded (seller, _, quantity) -> seller = Sim.playerId && quantity >= 1
+        | ObserveNotes, Observed -> true
+        | ReasonDebate, Dialogued _ -> true
         | _ -> false
 
     /// Offered → Active；其余状态原样返回（终态不可复活）。
@@ -145,7 +169,7 @@ module Occupation =
                 state <- next
         out
 
-    /// 当日任务生成：池内确定性抽 1 条；空池（货郎/书生首期）→ None。
+    /// 当日任务生成：池内确定性抽 1 条；空池 → None。
     /// TargetNpc/TargetTile 首期留 None（通配），OfferedTick/DueTick 覆盖整日。
     let dailyTaskOf (seed: uint64) (occupationSeed: uint64) (dayIndex: int64) (kind: Kind) : DailyTask option =
         match taskPoolOf kind with
@@ -161,6 +185,13 @@ module Occupation =
                   DueTick = offered + Sim.ticksPerDay - 1L
                   State = Offered }
 
+    /// 当日任务刷新：已持任务的 OfferedTick 仍落在 nowTick 所属日时原样保留（含
+    /// Done/Failed 终态，保证当日面板与存档稳定）；跨日才按当日重新生成 Offered。
+    let refreshToday (seed: uint64) (occupationSeed: uint64) (kind: Kind) (nowTick: int64) (today: DailyTask option) : DailyTask option =
+        match today with
+        | Some task when dayIndexOf task.OfferedTick = dayIndexOf nowTick -> Some task
+        | _ -> dailyTaskOf seed occupationSeed (dayIndexOf nowTick) kind
+
     /// 挂在玩家侧的职业状态，随存档 v3 保存（design §2）。
     /// Today = 当日任务（§3）；TaskToken 保留为 v3 前缀占位扩展位（恒 0，暂未启用）。
     type State =
@@ -172,6 +203,24 @@ module Occupation =
     let stateOf (kind: Kind) : State =
         { Profile = profileOf kind; TaskToken = 0; Today = None; StoryStage = 0 }
 
+    // ---- 既有事件通道 → 任务信号桥（design §3：完成判定统一走 InteractionEvent）----
+
+    /// 仅玩家发起的对话/交易才产生任务信号；NPC 之间互动的副作用不派任务。
+    /// TradeEvent 字段序 = buyer/seller/item/quantity/price，玩家为卖方 → Traded，为买方 → Purchased。
+    let signalOfInteraction (event: Sim.InteractionEvent) : TaskSignal option =
+        match event.Kind with
+        | Sim.DialogueEvent outcome when outcome.Actor = Sim.playerId -> Some(Dialogued outcome.Target)
+        | Sim.TradeEvent (_, seller, item, quantity, _) when seller = Sim.playerId -> Some(Traded(seller, item, quantity))
+        | Sim.TradeEvent (buyer, _, item, quantity, _) when buyer = Sim.playerId -> Some(Purchased(item, quantity))
+        | _ -> None
+
+    /// 用一条既有事件推进当日任务（Offered 须先 acceptTask；终态不可复活）。
+    /// 无职业 / 无当日任务 / 非玩家事件时原样返回。
+    let advanceTask (event: Sim.InteractionEvent) (state: State) : State =
+        match state.Today, signalOfInteraction event with
+        | Some task, Some signal -> { state with Today = Some(applySignal signal task) }
+        | _ -> state
+
     // ---- 报价偏置（design §2/§3）：Kernel 纯函数旁路，不改 Sim.fs 数值口径 ----
     // 4 位定点整数基点（1/10000）表达偏置，避免浮点漂移；结果钳在 [0.95, 1.05]。
     // 货郎：买卖双向有利（买压价/卖抬价 ±3.00%）；书生：解读行情小幅加成 ±1.00%；