M6.6: StepReview signing + hybrid math revision

- New Step VIII (Review): name input and Confirm button that
  saves the finalized character to user://character.tres.
- Hybrid lineage rules simplified per project decision: drop
  the "no-stack on overlap, take +1 free elsewhere" rule from
  theriapolis-rpg-clades.md. Hybrids now pick one ability mod
  from each parent clade and they sum if they overlap.
  Removes HybridFreeAbility, the free-bonus picker row, and the
  overlap special case from AbilityCalc + WizardValidation.
- StepClade bonus rows now mutate in place (sync ButtonPressed)
  instead of tearing down on every Refresh — the old path freed
  the very button mid-Pressed-signal, leaving stale buttons next
  to the new ones.
- StepSkills drops the redundant "Calling: X · History: Y" meta
  line; both are already shown in the Aside summary.
- Aside hybrid section adds dual-species traits and the
  universal-hybrid detriment pills.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Theriapolis.Godot/Scenes/Aside.cs

@@ -259,14 +259,21 @@ public partial class Aside : MarginContainer
             AddCladeTraits(flow, CodexContent.Clade(_draft.CladeId));
         }
 
-        // Species traits.
-        var sp = CodexContent.SpeciesById(_draft.EffectiveSpeciesId);
-        if (sp is not null)
+        // Species traits — purebred uses the single species; hybrids show
+        // BOTH parent species per theriapolis-rpg-clades.md ("Choose ONE
+        // species trait from each parent").
+        if (_draft.IsHybrid)
         {
-            foreach (var t in sp.Traits)
-                flow.AddChild(new TraitChip { TraitName = t.Name, Description = t.Description });
-            foreach (var d in sp.Detriments)
-                flow.AddChild(new TraitChip { TraitName = d.Name, Description = d.Description, Detriment = true });
+            AddSpeciesTraits(flow, CodexContent.SpeciesById(_draft.SireSpeciesId));
+            AddSpeciesTraits(flow, CodexContent.SpeciesById(_draft.DamSpeciesId));
+
+            // Universal hybrid detriments — every hybrid has all four.
+            foreach (var (name, desc) in UniversalHybridDetriments)
+                flow.AddChild(new TraitChip { TraitName = name, Description = desc, Detriment = true });
+        }
+        else
+        {
+            AddSpeciesTraits(flow, CodexContent.SpeciesById(_draft.SpeciesId));
         }
 
         // Class level-1 features.
@@ -321,6 +328,43 @@ public partial class Aside : MarginContainer
             flow.AddChild(new TraitChip { TraitName = d.Name, Description = d.Description, Detriment = true });
     }
 
+    private static void AddSpeciesTraits(HFlowContainer flow, Theriapolis.Core.Data.SpeciesDef? species)
+    {
+        if (species is null) return;
+        foreach (var t in species.Traits)
+            flow.AddChild(new TraitChip { TraitName = t.Name, Description = t.Description });
+        foreach (var d in species.Detriments)
+            flow.AddChild(new TraitChip { TraitName = d.Name, Description = d.Description, Detriment = true });
+    }
+
+    /// <summary>
+    /// Hardcoded from theriapolis-rpg-clades.md "Universal Hybrid Detriments"
+    /// (lines 749-753). Every hybrid character has all four. The schema
+    /// doesn't carry these yet — they live in the clades doc as canonical
+    /// rules text.
+    /// </summary>
+    private static readonly (string Name, string Description)[] UniversalHybridDetriments =
+    {
+        ("Scent Dysphoria",
+            "Your scent broadcasts conflicting Clade signals. Creatures with scent ability "
+          + "who detect you must make a WIS save (DC 10) or experience instinctive unease, "
+          + "imposing disadvantage on their first CHA check with you. Scent-masking products "
+          + "can suppress this for 1d4 hours but fail under stress."),
+        ("Illegible Body Language",
+            "Your tail and ear movements blend two Clade grammars. Disadvantage on nonverbal "
+          + "communication checks (CHA checks relying on body language) with purebred creatures. "
+          + "Other hybrids read you normally."),
+        ("Social Stigma",
+            "In non-progressive settlements, disadvantage on CHA checks with strangers and on "
+          + "checks to secure housing, employment, or official services. Even in progressive "
+          + "areas, the first CHA check with any new NPC is made at -2 until you've established "
+          + "rapport."),
+        ("Medical Incompatibility",
+            "Healing potions and magical healing function at 75% effectiveness (round down). "
+          + "Medical treatment calibrated for purebred physiologies works imperfectly on your "
+          + "blended body. Hybrid-specific medicine exists but is expensive and rare."),
+    };
+
     private static void AddSkillChip(HFlowContainer flow, string skillId, string tag)
     {
         var s = SkillsCatalog.Get(skillId);