Enhance protocol and simulation features with activity tracking and behavior definitions

- Updated protocol documentation to include new `activity` and `activityLabel` fields in the person card response, reflecting real-time activity status.
- Introduced `BehaviorDef` to define behavior rules, including need thresholds and lesson skill gains, enhancing AI decision-making.
- Revised the `DefCatalog` to incorporate behavior definitions and updated validation logic to ensure proper behavior handling.
- Enhanced the simulation to manage presence and activity states, allowing for more dynamic interactions within the school environment.
- Updated tests to validate the new activity tracking and behavior functionalities, ensuring robust performance and reliability.
- Improved localization strings to support new activity and behavior features, enhancing user experience.

src/HSchool.Ai/ActionStepper.cs

@@ -0,0 +1,53 @@
+using HSchool.Content;
+
+namespace HSchool.Ai;
+
+/// <summary>One in-progress action. <see cref="ActionId"/> is null when the person is idle.</summary>
+public readonly record struct ActivityProgress(string? ActionId, string? Thing, float RemainingMinutes)
+{
+    public static ActivityProgress Idle { get; } = new(null, null, 0f);
+
+    public bool IsActive => ActionId is not null;
+}
+
+/// <summary>
+/// Start, countdown and refill for one action. Occupancy is a count check — two people cannot
+/// take the last chair. Simulation copies this onto components; the library has no world.
+/// </summary>
+public static class ActionStepper
+{
+    public static ActivityProgress Begin(ActionDef def)
+    {
+        ArgumentNullException.ThrowIfNull(def);
+        var thing = string.IsNullOrWhiteSpace(def.Thing) ? null : def.Thing;
+        return new ActivityProgress(def.DefName, thing, def.Minutes);
+    }
+
+    public static ActivityProgress Advance(ActivityProgress activity, float minutes, out bool completed)
+    {
+        if (!activity.IsActive)
+        {
+            completed = false;
+            return activity;
+        }
+
+        var left = activity.RemainingMinutes - minutes;
+        if (left <= 0f)
+        {
+            completed = true;
+            return ActivityProgress.Idle;
+        }
+
+        completed = false;
+        return activity with { RemainingMinutes = left };
+    }
+
+    public static bool CanOccupy(int available, int occupied) => occupied < available;
+
+    public static float ApplyNeedGain(float current, ActionDef action, NeedDef need)
+    {
+        ArgumentNullException.ThrowIfNull(action);
+        ArgumentNullException.ThrowIfNull(need);
+        return Math.Clamp(current + action.NeedGain, need.Min, need.Max);
+    }
+}

src/HSchool.Ai/DayPlan.cs

@@ -12,8 +12,6 @@ public readonly record struct DayPlan(DateOnly Day, DateTime? AppearAt, DateTime
 
 public static class DayPlans
 {
-    private const int ExtraRollMax = 7;
-
     public static DayPlan Build(
         DefCatalog catalog,
         WalkGraph walks,
@@ -111,7 +109,15 @@ public static class DayPlans
     private static int SlackMinutes(DefCatalog catalog, Person person, int schoolSeed, DateOnly day)
     {
         var rng = new Random(Seed.Mix(schoolSeed, person.Id, day.DayNumber, Seed.CommuteSalt));
-        var extra = rng.Next(0, ExtraRollMax);
+        var min = 0;
+        var max = 6;
+        if (catalog.BehaviorRules is { } rules)
+        {
+            min = rules.CommuteSlackMin;
+            max = rules.CommuteSlackMax;
+        }
+
+        var extra = rng.Next(min, max + 1);
         foreach (var name in person.Traits)
         {
             if (catalog.Traits.TryGetValue(name, out var trait))