Add character detail, markdown rendering, wider layout, and LLM provider switch

- Character sheets gain structured combat_stats, abilities (name +
  plain-language explanation), and equipment fields, populated by the
  upsert_character_sheet tool; the detail page renders them as their
  own sections instead of one prose block, with a player-card-style
  attribute grid (full ability names + modifiers).
- Fix double-escaped unicode occasionally left in tool-call JSON
  arguments (a model quirk) and stop the app's own json.dumps calls
  from re-introducing it (ensure_ascii=False).
- Render chat messages as markdown (react-markdown + Tailwind
  typography) instead of raw text, and widen the games/characters/
  chat layout to use more of the screen on desktop.
- Sharpen the DM system prompt: state the ability + DC for each
  offered action option before the player commits, and narrate rolls
  as DC → result → pass/fail before the story consequence; also stop
  re-asking Session-0 questions already answered in the game's
  name/description.
- Make the DM's LLM provider configurable (xai default, lmstudio for
  a local OpenAI-compatible server via host.docker.internal) instead
  of hardcoded to x.ai.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/api/characters.ts

@@ -1,5 +1,10 @@
 import { apiFetch } from "./client";
 
+export interface CharacterAbility {
+  name: string;
+  description: string;
+}
+
 export interface Character {
   id: string;
   owner_id: string;
@@ -8,6 +13,9 @@ export interface Character {
   char_class: string | null;
   level: number;
   stats: Record<string, number>;
+  combat_stats: Record<string, string>;
+  abilities: CharacterAbility[];
+  equipment: string[];
   description: string;
   created_at: string;
   updated_at: string;

frontend/src/components/GameSetupChat.tsx

@@ -1,6 +1,7 @@
 import { FormEvent, useEffect, useRef, useState } from "react";
 
 import { createGame, Game, GameSetupProposal, runGameSetupChat } from "../api/games";
+import MarkdownContent from "./MarkdownContent";
 import SendMessageForm from "./SendMessageForm";
 
 interface DisplayTurn {
@@ -94,8 +95,8 @@ export default function GameSetupChat({ onCreated }: { onCreated: (game: Game) =
               }
             >
               {turn.role === "assistant" ? "Dungeon Master" : "Du"}:
-            </span>{" "}
-            <span className="whitespace-pre-wrap">{turn.content}</span>
+            </span>
+            <MarkdownContent content={turn.content} />
           </div>
         ))}
         {loading && <p className="text-sm text-slate-500">Der Dungeon Master überlegt…</p>}

frontend/src/components/MarkdownContent.tsx

@@ -0,0 +1,9 @@
+import ReactMarkdown from "react-markdown";
+
+export default function MarkdownContent({ content }: { content: string }) {
+  return (
+    <div className="prose prose-sm prose-invert max-w-none prose-p:my-1 prose-ul:my-1 prose-ol:my-1 prose-li:my-0 prose-headings:my-1">
+      <ReactMarkdown>{content}</ReactMarkdown>
+    </div>
+  );
+}

frontend/src/components/TranscriptPane.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useRef } from "react";
 
 import { Message } from "../api/games";
+import MarkdownContent from "./MarkdownContent";
 
 function senderLabel(message: Message): string {
   if (message.sender_type === "dm") return "Dungeon Master";
@@ -36,8 +37,8 @@ export default function TranscriptPane({
             }
           >
             {senderLabel(m)}:
-          </span>{" "}
-          <span className="whitespace-pre-wrap">{m.content}</span>
+          </span>
+          <MarkdownContent content={m.content} />
         </div>
       ))}
       {typing && (

frontend/src/pages/CharacterDetail.tsx

@@ -3,6 +3,30 @@ import { Link, useParams, useSearchParams } from "react-router-dom";
 
 import { Character, getCharacter } from "../api/characters";
 
+const ABILITY_NAMES: Record<string, string> = {
+  STR: "Stärke",
+  DEX: "Geschicklichkeit",
+  CON: "Konstitution",
+  INT: "Intelligenz",
+  WIS: "Weisheit",
+  CHA: "Charisma",
+};
+
+const ABILITY_ORDER = ["STR", "DEX", "CON", "INT", "WIS", "CHA"];
+
+function orderedStats(stats: Record<string, number>): [string, number][] {
+  const known = ABILITY_ORDER.filter((key) => key in stats).map(
+    (key) => [key, stats[key]] as [string, number],
+  );
+  const unknown = Object.entries(stats).filter(([key]) => !ABILITY_ORDER.includes(key));
+  return [...known, ...unknown];
+}
+
+function modifier(score: number): string {
+  const mod = Math.floor((score - 10) / 2);
+  return mod >= 0 ? `+${mod}` : `${mod}`;
+}
+
 export default function CharacterDetail() {
   const { characterId } = useParams<{ characterId: string }>();
   const [searchParams] = useSearchParams();
@@ -22,7 +46,7 @@ export default function CharacterDetail() {
   if (!character) return <p className="p-8 text-slate-400">Charakter nicht gefunden.</p>;
 
   return (
-    <div className="mx-auto max-w-2xl px-4 py-8">
+    <div className="mx-auto max-w-6xl px-4 py-8">
       {backGameId && (
         <Link
           to={`/games/${backGameId}`}
@@ -32,24 +56,96 @@ export default function CharacterDetail() {
         </Link>
       )}
 
-      <h1 className="text-2xl font-bold text-amber-400">{character.name}</h1>
-      <p className="mt-1 text-slate-400">
-        {character.race ?? "?"} · {character.char_class ?? "?"} · Stufe {character.level}
-      </p>
+      <div className="rounded-lg border border-amber-500/30 bg-slate-900 p-6">
+        <h1 className="text-3xl font-bold text-amber-400">{character.name}</h1>
+        <p className="mt-1 text-slate-400">
+          {character.race ?? "?"} · {character.char_class ?? "?"} · Stufe {character.level}
+        </p>
+      </div>
 
       {Object.keys(character.stats).length > 0 && (
-        <div className="mt-4 grid grid-cols-3 gap-3 sm:grid-cols-6">
-          {Object.entries(character.stats).map(([stat, value]) => (
-            <div key={stat} className="rounded bg-slate-800 p-2 text-center">
-              <div className="text-xs uppercase text-slate-500">{stat}</div>
-              <div className="text-lg font-semibold text-slate-100">{value}</div>
-            </div>
-          ))}
+        <div className="mt-6">
+          <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-slate-500">
+            Attribute
+          </h2>
+          <div className="grid grid-cols-2 gap-3 sm:grid-cols-3 lg:grid-cols-6">
+            {orderedStats(character.stats).map(([key, value]) => (
+              <div
+                key={key}
+                className="flex flex-col items-center rounded-lg border border-slate-700 bg-slate-800 py-4"
+              >
+                <div className="text-xs font-semibold uppercase tracking-wide text-slate-400">
+                  {ABILITY_NAMES[key] ?? key}
+                </div>
+                <div className="mt-1 text-3xl font-bold text-slate-100">{value}</div>
+                <div className="mt-1 rounded-full bg-slate-700 px-2 py-0.5 text-sm font-semibold text-amber-400">
+                  {modifier(value)}
+                </div>
+              </div>
+            ))}
+          </div>
         </div>
       )}
 
-      <div className="mt-6 whitespace-pre-wrap rounded-lg border border-slate-800 bg-slate-900 p-4 text-slate-300">
-        {character.description || "Noch keine Beschreibung."}
+      {Object.keys(character.combat_stats).length > 0 && (
+        <div className="mt-6">
+          <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-slate-500">
+            Kampfwerte
+          </h2>
+          <div className="flex flex-wrap gap-3">
+            {Object.entries(character.combat_stats).map(([key, value]) => (
+              <div
+                key={key}
+                className="rounded-lg border border-slate-700 bg-slate-800 px-4 py-2 text-center"
+              >
+                <div className="text-xs font-semibold uppercase tracking-wide text-slate-400">
+                  {key}
+                </div>
+                <div className="text-lg font-bold text-slate-100">{value}</div>
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+
+      {character.abilities.length > 0 && (
+        <div className="mt-6">
+          <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-slate-500">
+            Fähigkeiten &amp; Merkmale
+          </h2>
+          <div className="flex flex-col gap-3">
+            {character.abilities.map((ability, i) => (
+              <div key={i} className="rounded-lg border border-slate-800 bg-slate-900 p-4">
+                <h3 className="font-semibold text-amber-400">{ability.name}</h3>
+                <p className="mt-1 whitespace-pre-wrap text-sm text-slate-300">
+                  {ability.description}
+                </p>
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+
+      {character.equipment.length > 0 && (
+        <div className="mt-6">
+          <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-slate-500">
+            Ausrüstung
+          </h2>
+          <ul className="list-disc rounded-lg border border-slate-800 bg-slate-900 p-4 pl-8 text-slate-300">
+            {character.equipment.map((item, i) => (
+              <li key={i}>{item}</li>
+            ))}
+          </ul>
+        </div>
+      )}
+
+      <div className="mt-6">
+        <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-slate-500">
+          Hintergrundgeschichte
+        </h2>
+        <div className="whitespace-pre-wrap rounded-lg border border-slate-800 bg-slate-900 p-4 text-slate-300">
+          {character.description || "Noch keine Beschreibung."}
+        </div>
       </div>
     </div>
   );

frontend/src/pages/CharactersList.tsx

@@ -14,7 +14,7 @@ export default function CharactersList() {
   }, []);
 
   return (
-    <div className="mx-auto max-w-3xl px-4 py-8">
+    <div className="mx-auto max-w-6xl px-4 py-8">
       <h1 className="mb-6 text-2xl font-bold text-amber-400">Charaktere</h1>
       {loading ? (
         <p className="text-slate-400">Lädt…</p>
@@ -23,7 +23,7 @@ export default function CharactersList() {
           Noch keine Charaktere — sie entstehen im Laufe eines Spiels.
         </p>
       ) : (
-        <div className="grid gap-3 sm:grid-cols-2">
+        <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
           {characters.map((c) => (
             <CharacterCard key={c.id} character={c} />
           ))}

frontend/src/pages/ForgotPassword.tsx

@@ -14,7 +14,7 @@ export default function ForgotPassword() {
   }
 
   return (
-    <div className="mx-auto mt-16 max-w-sm px-4">
+    <div className="mx-auto mt-16 max-w-md px-4">
       <h1 className="mb-6 text-2xl font-bold text-amber-400">Passwort vergessen</h1>
       {sent ? (
         <p className="text-slate-300">

frontend/src/pages/GameSession.tsx

@@ -114,7 +114,7 @@ export default function GameSession() {
 
   if (!game.is_participant) {
     return (
-      <div className="mx-auto mt-16 max-w-sm px-4">
+      <div className="mx-auto mt-16 max-w-md px-4">
         <h1 className="mb-2 text-2xl font-bold text-amber-400">{game.name}</h1>
         <p className="mb-6 text-sm text-slate-400">{game.description}</p>
         <form onSubmit={handleJoin} className="flex flex-col gap-4">
@@ -152,7 +152,7 @@ export default function GameSession() {
   }
 
   return (
-    <div className="mx-auto flex h-[calc(100vh-56px)] max-w-3xl flex-col px-4 py-4">
+    <div className="mx-auto flex h-[calc(100vh-56px)] max-w-6xl flex-col px-4 py-4">
       <div className="mb-3 flex items-center justify-between">
         <div>
           <h1 className="text-xl font-bold text-amber-400">{game.name}</h1>

frontend/src/pages/GamesList.tsx

@@ -25,7 +25,7 @@ export default function GamesList() {
   }, []);
 
   return (
-    <div className="mx-auto max-w-3xl px-4 py-8">
+    <div className="mx-auto max-w-6xl px-4 py-8">
       <div className="mb-6 flex items-center justify-between">
         <h1 className="text-2xl font-bold text-amber-400">Spiele</h1>
         <div className="flex gap-2">
@@ -45,7 +45,7 @@ export default function GamesList() {
       ) : games.length === 0 ? (
         <p className="text-slate-400">Noch keine Spiele vorhanden.</p>
       ) : (
-        <div className="flex flex-col gap-3">
+        <div className="grid gap-3 sm:grid-cols-2 xl:grid-cols-3">
           {games.map((game) => (
             <GameCard key={game.id} game={game} />
           ))}

frontend/src/pages/Login.tsx

@@ -26,7 +26,7 @@ export default function Login() {
   }
 
   return (
-    <div className="mx-auto mt-16 max-w-sm px-4">
+    <div className="mx-auto mt-16 max-w-md px-4">
       <h1 className="mb-6 text-2xl font-bold text-amber-400">Anmelden</h1>
       <form onSubmit={handleSubmit} className="flex flex-col gap-4">
         <input

frontend/src/pages/Register.tsx

@@ -27,7 +27,7 @@ export default function Register() {
   }
 
   return (
-    <div className="mx-auto mt-16 max-w-sm px-4">
+    <div className="mx-auto mt-16 max-w-md px-4">
       <h1 className="mb-6 text-2xl font-bold text-amber-400">Registrieren</h1>
       <form onSubmit={handleSubmit} className="flex flex-col gap-4">
         <input

frontend/src/pages/ResetPassword.tsx

@@ -25,7 +25,7 @@ export default function ResetPassword() {
 
   if (!token) {
     return (
-      <div className="mx-auto mt-16 max-w-sm px-4 text-slate-300">
+      <div className="mx-auto mt-16 max-w-md px-4 text-slate-300">
         Kein gültiger Reset-Link.{" "}
         <Link to="/forgot-password" className="text-amber-400">
           Neu anfordern
@@ -35,7 +35,7 @@ export default function ResetPassword() {
   }
 
   return (
-    <div className="mx-auto mt-16 max-w-sm px-4">
+    <div className="mx-auto mt-16 max-w-md px-4">
       <h1 className="mb-6 text-2xl font-bold text-amber-400">Neues Passwort setzen</h1>
       {done ? (
         <p className="text-slate-300">Passwort geändert. Du wirst weitergeleitet…</p>