Add talk circles with TopicDef, staff/phone chat, and opinion outcomes.

src/HSchool.Content/CatalogLoader.cs

@@ -315,6 +315,7 @@ public sealed class CatalogLoader
         var holidays = new Dictionary<string, HolidayDef>(StringComparer.Ordinal);
         var behavior = new Dictionary<string, BehaviorDef>(StringComparer.Ordinal);
         var colors = new Dictionary<string, ColorDef>(StringComparer.Ordinal);
+        var topics = new Dictionary<string, TopicDef>(StringComparer.Ordinal);
 
         foreach (var (key, json) in resolved)
         {
@@ -380,6 +381,9 @@ public sealed class CatalogLoader
                 case DefKind.Color:
                     colors[key.Name] = Jsonc.Deserialize<ColorDef>(json);
                     break;
+                case DefKind.Topic:
+                    topics[key.Name] = Jsonc.Deserialize<TopicDef>(json);
+                    break;
             }
         }
 
@@ -405,6 +409,7 @@ public sealed class CatalogLoader
             holidays,
             behavior,
             colors,
+            topics,
             ru,
             en);
     }

src/HSchool.Content/DefCatalog.cs

@@ -28,6 +28,7 @@ public sealed class DefCatalog
         IReadOnlyDictionary<string, HolidayDef> holidays,
         IReadOnlyDictionary<string, BehaviorDef> behavior,
         IReadOnlyDictionary<string, ColorDef> colors,
+        IReadOnlyDictionary<string, TopicDef> topics,
         IReadOnlyDictionary<string, string> ru,
         IReadOnlyDictionary<string, string> en)
     {
@@ -52,6 +53,7 @@ public sealed class DefCatalog
         Holidays = holidays;
         Behavior = behavior;
         Colors = colors;
+        Topics = topics;
         _ru = ru;
         _en = en;
         AnyNeedDecays = needs.Values.Any(need => !need.Abstract && need.DecayPerHour > 0f);
@@ -109,6 +111,8 @@ public sealed class DefCatalog
 
     public IReadOnlyDictionary<string, ColorDef> Colors { get; }
 
+    public IReadOnlyDictionary<string, TopicDef> Topics { get; }
+
     /// <summary>The one concrete staffing ruleset, or null when a pack has not defined it.</summary>
     public StaffingDef? StaffingRules => Staffing.Values.FirstOrDefault(def => !def.Abstract);
 
@@ -145,6 +149,7 @@ public sealed class DefCatalog
             DefKind.Holiday => Holidays.GetValueOrDefault(defName),
             DefKind.Behavior => Behavior.GetValueOrDefault(defName),
             DefKind.Color => Colors.GetValueOrDefault(defName),
+            DefKind.Topic => Topics.GetValueOrDefault(defName),
             _ => null,
         };
 
@@ -225,6 +230,7 @@ public sealed class DefCatalog
         HolidayDef => DefKind.Holiday,
         BehaviorDef => DefKind.Behavior,
         ColorDef => DefKind.Color,
+        TopicDef => DefKind.Topic,
         _ => throw new ArgumentOutOfRangeException(nameof(def)),
     };
 

src/HSchool.Content/Defs.cs

@@ -22,6 +22,7 @@ public enum DefKind
     Holiday,
     Behavior,
     Color,
+    Topic,
 }
 
 /// <summary>Shared JSONC fields. Kind comes from the folder under <c>defs/</c>, not from the file.</summary>

src/HSchool.Content/PackPaths.cs

@@ -129,6 +129,9 @@ internal static class PackPaths
             case "colors":
                 kind = DefKind.Color;
                 return true;
+            case "topics":
+                kind = DefKind.Topic;
+                return true;
             default:
                 kind = default;
                 return false;

src/HSchool.Content/PeopleDefValidator.cs

@@ -65,6 +65,13 @@ internal static class PeopleDefValidator
             ValidateBehavior(behavior, log);
         }
 
+        foreach (var topic in catalog.Topics.Values)
+        {
+            ValidateTopic(topic, catalog);
+        }
+
+        RequireTalkTopics(catalog);
+
         if (catalog.Staffing.Values.Count(def => !def.Abstract) > 1)
         {
             throw new ContentLoadException("A catalog may only have one concrete StaffingDef.");
@@ -550,6 +557,63 @@ internal static class PeopleDefValidator
             log.Warning(
                 $"BehaviorDef '{behavior.DefName}' lunchWeight {behavior.LunchWeight} is above dutyLessonWeight {behavior.DutyLessonWeight}; pupils will leave class for lunch.");
         }
+
+        if (behavior.TalkCircleMin < 2 || behavior.TalkCircleMax < behavior.TalkCircleMin)
+        {
+            throw new ContentLoadException(
+                $"BehaviorDef '{behavior.DefName}' talk circle size must be at least 2 with max ≥ min.");
+        }
+    }
+
+    private static void ValidateTopic(TopicDef topic, DefCatalog catalog)
+    {
+        if (topic.Abstract)
+        {
+            return;
+        }
+
+        if (topic.Tags.Count == 0)
+        {
+            throw new ContentLoadException($"TopicDef '{topic.DefName}' needs at least one tag.");
+        }
+
+        if (topic.Age is { Min: var min, Max: var max } && min > max)
+        {
+            throw new ContentLoadException($"TopicDef '{topic.DefName}' age min cannot exceed max.");
+        }
+
+        foreach (var role in topic.Roles)
+        {
+            if (!PersonRoles.IsKnown(role))
+            {
+                throw new ContentLoadException($"TopicDef '{topic.DefName}' has unknown role '{role}'.");
+            }
+        }
+
+        if (topic.Language is not null && !catalog.Skills.ContainsKey(topic.Language))
+        {
+            throw new ContentLoadException($"TopicDef '{topic.DefName}' references unknown SkillDef '{topic.Language}'.");
+        }
+    }
+
+    /// <summary>A catalog with circle actions but no topics would silently solo-chat — refuse load.</summary>
+    private static void RequireTalkTopics(DefCatalog catalog)
+    {
+        var hasTalkAction = catalog.Actions.Values.Any(action =>
+            !action.Abstract
+            && (action.DefName.Equals(TalkActions.Chat, StringComparison.Ordinal)
+                || action.DefName.Equals(TalkActions.StaffChat, StringComparison.Ordinal)
+                || action.DefName.Equals(TalkActions.PhoneChat, StringComparison.Ordinal)));
+        if (!hasTalkAction)
+        {
+            return;
+        }
+
+        if (!catalog.Topics.Values.Any(topic => !topic.Abstract))
+        {
+            throw new ContentLoadException(
+                "A catalog with talk actions requires at least one concrete TopicDef.");
+        }
     }
 
     private static void ValidateConditionBands(BehaviorDef behavior)

src/HSchool.Content/PeopleDefs.cs

@@ -162,6 +162,14 @@ public sealed class TraitSkillModifier
     public int Offset { get; init; }
 }
 
+/// <summary>Biases topic pick toward a tag. Used on gossip and similar traits.</summary>
+public sealed class TopicTagWeight
+{
+    public required string Tag { get; init; }
+
+    public float Weight { get; init; } = 1f;
+}
+
 public sealed class TraitDef : Def
 {
     public int Weight { get; init; } = 1;
@@ -190,6 +198,39 @@ public sealed class TraitDef : Def
     /// cold-loving is negative.
     /// </summary>
     public float ComfortTemperatureOffset { get; init; }
+
+    /// <summary>How often this person initiates talk. Quiet below 1, leader above.</summary>
+    public float TalkInitiative { get; init; } = 1f;
+
+    /// <summary>Extra seats preferred in a circle. Social trait raises it.</summary>
+    public int TalkCircleBonus { get; init; }
+
+    /// <summary>Multiplies opinion shift from talk. Gossip above 1.</summary>
+    public float TalkOpinionMultiplier { get; init; } = 1f;
+
+    /// <summary>Pull toward topics carrying these tags when this person picks the subject.</summary>
+    public IReadOnlyList<TopicTagWeight> TalkTagWeights { get; init; } = [];
+}
+
+/// <summary>Conversation subject. Tags gate appropriateness; language is optional skill help.</summary>
+public sealed class TopicDef : Def
+{
+    /// <summary>Vanilla tags: study, games, food, family, sport, gossip, rude, appearance.</summary>
+    public IReadOnlyList<string> Tags { get; init; } = [];
+
+    public IntRange? Age { get; init; }
+
+    /// <summary>Empty means every role.</summary>
+    public IReadOnlyList<string> Roles { get; init; } = [];
+
+    /// <summary>Allowed as whisper on lesson — phase 43 uses this; ordinary Chat does not.</summary>
+    public bool WhisperOnLesson { get; init; }
+
+    /// <summary>Skill that helps when shared above threshold. Null — any language works equally.</summary>
+    public string? Language { get; init; }
+
+    /// <summary>Base opinion shift toward each other participant when talk succeeds.</summary>
+    public int OpinionShift { get; init; } = 2;
 }
 
 public sealed class StaffingDef : Def
@@ -329,6 +370,36 @@ public sealed class BehaviorDef : Def
     /// </summary>
     public IReadOnlyList<OpinionBand> OpinionBands { get; init; } = DefaultOpinionBands;
 
+    /// <summary>Skill points Communication gains per game hour of talk — less than a lesson.</summary>
+    public float TalkSkillPerHour { get; init; } = 0.02f;
+
+    /// <summary>Language used in talk, when not already at skill max.</summary>
+    public float TalkLanguageSkillPerHour { get; init; } = 0.005f;
+
+    /// <summary>Minimum shared language skill for full opinion shift.</summary>
+    public int TalkLanguageThreshold { get; init; } = 25;
+
+    /// <summary>Opinion multiplier when participants share no language above threshold.</summary>
+    public float TalkNoLanguageOpinionMultiplier { get; init; } = 0.15f;
+
+    /// <summary>Opinion multiplier for phone chat vs live circle.</summary>
+    public float TalkPhoneOpinionMultiplier { get; init; } = 0.5f;
+
+    /// <summary>How much Communication scales opinion shift (per 100 points).</summary>
+    public float TalkCommunicationOpinionScale { get; init; } = 0.5f;
+
+    /// <summary>Minimum circle size. Below this Chat does not start.</summary>
+    public int TalkCircleMin { get; init; } = 2;
+
+    /// <summary>Maximum people in one live circle.</summary>
+    public int TalkCircleMax { get; init; } = 4;
+
+    /// <summary>Opinion at or above — friend for invites and node pull.</summary>
+    public int TalkFriendThreshold { get; init; } = 40;
+
+    /// <summary>Opinion at or below — enemy; never invited, lunch nodes avoided.</summary>
+    public int TalkEnemyThreshold { get; init; } = -40;
+
     public static IReadOnlyList<OpinionBand> DefaultOpinionBands { get; } =
     [
         new() { Min = 70, Id = "OpinionCloseFriend" },

src/HSchool.Content/TalkActions.cs

@@ -0,0 +1,28 @@
+namespace HSchool.Content;
+
+/// <summary>Leisure actions that form talk circles. Names match ActionDef ids in core.</summary>
+public static class TalkActions
+{
+    public const string Chat = "Chat";
+    public const string StaffChat = "StaffChat";
+    public const string PhoneChat = "PhoneChat";
+
+    public static bool IsTalk(string? actionId) =>
+        actionId is not null
+        && (actionId.Equals(Chat, StringComparison.Ordinal)
+            || actionId.Equals(StaffChat, StringComparison.Ordinal)
+            || actionId.Equals(PhoneChat, StringComparison.Ordinal));
+}
+
+/// <summary>Vanilla topic tags from the social slice design doc.</summary>
+public static class TopicTags
+{
+    public const string Study = "study";
+    public const string Games = "games";
+    public const string Food = "food";
+    public const string Family = "family";
+    public const string Sport = "sport";
+    public const string Gossip = "gossip";
+    public const string Rude = "rude";
+    public const string Appearance = "appearance";
+}