Theme neo-brutaliste + panneau raisonnement + repli sans outils

UI : reskin complet vers un theme neo-brutaliste clair (bordures noires 3px,
ombres dures, accent orange, polices Press Start 2P + DM Mono).
- tailwind.config / index.css / index.html : palette, polices, ombres, scrollbars
- TopBar, ActivityBar, LeftPanel, ChatPanel, PreviewPanel, SettingsView,
  ToolCard, ModelSelector, Icon : restyle complet

Chat : panneau « Raisonnement » repliable et redimensionnable affichant le
thinking de l'agent en direct (diffuse depuis le backend, persiste dans meta).

Robustesse Ollama : les echecs de generation de parseur d'outils
(« Unable to generate parser for this template ») declenchent desormais le
repli automatique en conversation simple sans outils, au lieu d'un 400.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/tailwind.config.ts

@@ -1,8 +1,9 @@
 import type { Config } from "tailwindcss";
 
 /**
- * Système de design « Loki » — extrait fidèlement du visuel Atelier_Agent.
- * Thème sombre chaleureux (café / ambre).
+ * Système de design « Loki » — thème néo-brutaliste clair.
+ * Bordures noires épaisses, ombres dures décalées, accent orange,
+ * police pixel (Press Start 2P) pour les libellés, DM Mono pour le corps.
  */
 export default {
   content: ["./index.html", "./src/**/*.{ts,tsx}"],
@@ -10,48 +11,60 @@ export default {
     extend: {
       colors: {
         // Fonds
-        base: "#1a1714",
-        bar: "#1d1a15",
-        panel: "#1c1814",
-        sunken: "#161310",
+        base: "#ececef", // contenu principal
+        bar: "#18181b", // chrome sombre (barres)
+        panel: "#fafafa", // panneaux latéraux
+        sunken: "#18181b", // encarts sombres (code, invite système)
         // Surfaces / cartes
-        card: "#211d18",
-        "card-soft": "#221e18",
-        "card-deep": "#1f1b16",
+        card: "#ffffff",
+        "card-soft": "#fafafa",
+        "card-deep": "#18181b",
         // Bordures
-        line: "#2c2720",
-        "line-soft": "#262219",
-        "line-strong": "#322d26",
-        // Accent ambre
-        accent: "#f0a15c",
-        "accent-1": "#f4ad6c",
-        "accent-2": "#df7c4c",
+        line: "#18181b", // bordure noire signature
+        "line-soft": "#e4e4e7", // séparateur clair
+        "line-strong": "#18181b",
+        // Accent orange
+        accent: "#ff5436",
+        "accent-1": "#ff6b50",
+        "accent-2": "#e23e22",
         // Statuts
-        ok: "#86c79a",
-        info: "#5b8fb0",
-        warn: "#c98b5b",
-        // Textes
-        ink: "#efe9df",
-        "ink-2": "#cfc5b6",
-        "ink-3": "#bdb3a4",
-        muted: "#9a9082",
-        "muted-2": "#8a8175",
-        "muted-3": "#766d60",
-        "muted-4": "#6a6256",
-        label: "#7a7164",
+        ok: "#22c55e",
+        info: "#3b82f6",
+        warn: "#dc2626",
+        // Textes (sombres sur fond clair)
+        ink: "#18181b",
+        "ink-2": "#27272a",
+        "ink-3": "#3f3f46",
+        muted: "#52525b",
+        "muted-2": "#71717a",
+        "muted-3": "#a1a1aa",
+        "muted-4": "#a1a1aa",
+        label: "#52525b",
+        // Teintes claires utiles sur le chrome sombre
+        "chrome-2": "#27272a",
+        "chrome-3": "#3f3f46",
+        "on-dark": "#e4e4e7",
+        "on-dark-2": "#a1a1aa",
+        "on-dark-3": "#71717a",
       },
       fontFamily: {
-        sans: ['"Hanken Grotesk"', "system-ui", "sans-serif"],
-        mono: ['"JetBrains Mono"', "ui-monospace", "monospace"],
+        sans: ['"DM Mono"', "ui-monospace", "monospace"],
+        mono: ['"DM Mono"', "ui-monospace", "monospace"],
+        pixel: ['"Press Start 2P"', "ui-monospace", "monospace"],
       },
       borderRadius: {
-        card: "14px",
+        card: "9px",
       },
       boxShadow: {
-        frame: "0 24px 60px rgba(0,0,0,.35)",
+        "hard-sm": "3px 3px 0 #18181b",
+        hard: "4px 4px 0 #18181b",
+        "hard-lg": "7px 7px 0 #18181b",
+        "hard-accent": "3px 3px 0 #ff5436",
+        "accent-soft": "3px 3px 0 rgba(255,84,54,.4)",
+        frame: "4px 4px 0 #18181b",
       },
       backgroundImage: {
-        "accent-grad": "linear-gradient(140deg, #f4ad6c, #df7c4c)",
+        "accent-grad": "linear-gradient(140deg, #ff6b50, #e23e22)",
       },
     },
   },