feat: add collapse/expand all tool calls toggle button

Adds a floating button in the chat area that lets users collapse or expand
all tool call details at once. Useful for long conversations with many tool
calls where scrolling through expanded results is tedious.

- New ToolCollapseContext provides global collapse/expand state
- ToolCall components react to global state changes via version tracking
- Toggle button appears only when conversation has tool calls
- Supports EN/FR i18n

src/App.tsx

@@ -6,6 +6,7 @@ import { Sidebar } from './components/Sidebar';
 import { LoginScreen } from './components/LoginScreen';
 import { ConnectionBanner } from './components/ConnectionBanner';
 import { KeyboardShortcuts } from './components/KeyboardShortcuts';
+import { ToolCollapseProvider } from './contexts/ToolCollapseContext';
 
 const Chat = lazy(() => import('./components/Chat').then(m => ({ default: m.Chat })));
 
@@ -85,6 +86,7 @@ export default function App() {
   }
 
   return (
+    <ToolCollapseProvider>
     <div className="h-dvh flex overflow-x-hidden bg-[#1e1e24] text-zinc-300 bg-[radial-gradient(ellipse_at_top,rgba(255,255,255,0.02),transparent_50%),radial_gradient(ellipse_at_bottom_right,rgba(99,102,241,0.04),transparent_50%)]" role="application" aria-label="PinchChat">
       <Sidebar
         sessions={sessions}
@@ -103,5 +105,6 @@ export default function App() {
       </div>
       <KeyboardShortcuts open={shortcutsOpen} onClose={() => setShortcutsOpen(false)} />
     </div>
+    </ToolCollapseProvider>
   );
 }

src/components/Chat.tsx

@@ -3,9 +3,10 @@ import { ChatMessageComponent } from './ChatMessage';
 import { ChatInput } from './ChatInput';
 import { TypingIndicator } from './TypingIndicator';
 import type { ChatMessage, ConnectionStatus } from '../types';
-import { Bot, ArrowDown, Loader2 } from 'lucide-react';
+import { Bot, ArrowDown, Loader2, ChevronsDownUp, ChevronsUpDown } from 'lucide-react';
 import { useT } from '../hooks/useLocale';
 import { getLocale, type TranslationKey } from '../lib/i18n';
+import { useToolCollapse } from '../contexts/ToolCollapseContext';
 
 interface Props {
   messages: ChatMessage[];
@@ -126,6 +127,9 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
 
   const showTyping = isGenerating && !hasStreamedText(messages);
 
+  const { globalState, collapseAll, expandAll } = useToolCollapse();
+  const hasToolCalls = useMemo(() => messages.some(m => m.blocks.some(b => b.type === 'tool_use' || b.type === 'tool_result')), [messages]);
+
   return (
     <div className="flex-1 flex flex-col min-h-0 relative">
       <div ref={scrollContainerRef} className="flex-1 overflow-y-auto overflow-x-hidden relative" role="log" aria-label={t('chat.messages')} aria-live="polite">
@@ -164,9 +168,19 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
           <div ref={bottomRef} />
         </div>
       </div>
-      {/* Scroll to bottom FAB */}
-      {showScrollBtn && (
-        <div className="absolute bottom-24 left-1/2 -translate-x-1/2 z-10">
+      {/* Floating action buttons */}
+      <div className="absolute bottom-24 left-1/2 -translate-x-1/2 z-10 flex items-center gap-2">
+        {hasToolCalls && (
+          <button
+            onClick={globalState === 'expand-all' ? collapseAll : expandAll}
+            aria-label={globalState === 'expand-all' ? t('chat.collapseTools') : t('chat.expandTools')}
+            title={globalState === 'expand-all' ? t('chat.collapseTools') : t('chat.expandTools')}
+            className="flex items-center gap-1.5 rounded-full border border-white/10 bg-zinc-800/90 backdrop-blur-lg px-3 py-2 text-xs text-zinc-300 shadow-lg hover:bg-zinc-700/90 transition-all hover:shadow-violet-500/10"
+          >
+            {globalState === 'expand-all' ? <ChevronsDownUp size={14} className="text-violet-300" /> : <ChevronsUpDown size={14} className="text-violet-300" />}
+          </button>
+        )}
+        {showScrollBtn && (
           <button
             onClick={() => scrollToBottom('smooth')}
             aria-label={t('chat.scrollToBottom')}
@@ -175,8 +189,8 @@ export function Chat({ messages, isGenerating, isLoadingHistory, status, session
             <ArrowDown size={14} className="text-cyan-300" />
             <span className="hidden sm:inline">{t('chat.scrollToBottom')}</span>
           </button>
-        </div>
-      )}
+        )}
+      </div>
       <ChatInput onSend={handleSend} onAbort={onAbort} isGenerating={isGenerating} disabled={status !== 'connected'} sessionKey={sessionKey} />
     </div>
   );

src/components/ToolCall.tsx

@@ -1,8 +1,9 @@
-import { useState, useCallback, useMemo } from 'react';
+import { useState, useCallback, useMemo, useEffect, useRef } from 'react';
 import { ChevronRight, ChevronDown, Check, Copy } from 'lucide-react';
 import hljs from 'highlight.js/lib/common';
 import { useT } from '../hooks/useLocale';
 import { ImageBlock } from './ImageBlock';
+import { useToolCollapse } from '../contexts/ToolCollapseContext';
 
 type ToolColor = { border: string; bg: string; text: string; icon: string; glow: string; expandBorder: string; expandBg: string };
 
@@ -217,8 +218,19 @@ function extractImageFromResult(result: string): { src: string; remaining: strin
 export function ToolCall({ name, input, result }: { name: string; input?: Record<string, unknown>; result?: string }) {
   const t = useT();
   const [open, setOpen] = useState(false);
+  const { globalState, version } = useToolCollapse();
+  const lastVersion = useRef(version);
   const c = getColor(name);
 
+  // Respond to global collapse/expand commands
+  useEffect(() => {
+    if (version !== lastVersion.current) {
+      lastVersion.current = version;
+      if (globalState === 'collapse-all') setOpen(false);
+      else if (globalState === 'expand-all') setOpen(true);
+    }
+  }, [globalState, version]);
+
   const inputStr = input ? (typeof input === 'string' ? input : JSON.stringify(input, null, 2)) : '';
   const hint = getContextHint(name, input);
 

src/contexts/ToolCollapseContext.tsx

@@ -0,0 +1,44 @@
+import { createContext, useContext, useState, useCallback, type ReactNode } from 'react';
+
+type ToolCollapseState = 'none' | 'collapse-all' | 'expand-all';
+
+interface ToolCollapseContextValue {
+  /** Global override: 'none' means each tool manages its own state */
+  globalState: ToolCollapseState;
+  /** Monotonically increasing version — tool calls reset local state when this changes */
+  version: number;
+  collapseAll: () => void;
+  expandAll: () => void;
+}
+
+const ToolCollapseContext = createContext<ToolCollapseContextValue>({
+  globalState: 'none',
+  version: 0,
+  collapseAll: () => {},
+  expandAll: () => {},
+});
+
+export function ToolCollapseProvider({ children }: { children: ReactNode }) {
+  const [globalState, setGlobalState] = useState<ToolCollapseState>('none');
+  const [version, setVersion] = useState(0);
+
+  const collapseAll = useCallback(() => {
+    setGlobalState('collapse-all');
+    setVersion(v => v + 1);
+  }, []);
+
+  const expandAll = useCallback(() => {
+    setGlobalState('expand-all');
+    setVersion(v => v + 1);
+  }, []);
+
+  return (
+    <ToolCollapseContext.Provider value={{ globalState, version, collapseAll, expandAll }}>
+      {children}
+    </ToolCollapseContext.Provider>
+  );
+}
+
+export function useToolCollapse() {
+  return useContext(ToolCollapseContext);
+}

src/lib/i18n.ts

@@ -41,6 +41,8 @@ const en = {
   'chat.send': 'Send',
   'chat.stop': 'Stop',
   'chat.scrollToBottom': 'New messages',
+  'chat.collapseTools': 'Collapse all tools',
+  'chat.expandTools': 'Expand all tools',
   'chat.messages': 'Chat messages',
   'chat.thinking': 'Thinking…',
 
@@ -131,6 +133,8 @@ const fr: Record<keyof typeof en, string> = {
   'chat.send': 'Envoyer',
   'chat.stop': 'Arrêter',
   'chat.scrollToBottom': 'Nouveaux messages',
+  'chat.collapseTools': 'Replier tous les outils',
+  'chat.expandTools': 'Déplier tous les outils',
   'chat.messages': 'Messages du chat',
   'chat.thinking': 'Réflexion…',