feat: improve VS Code dev flow and stabilize sidebar/chat behavior (#754)

* fix: improve session sidebar tooltip and truncation behavior

- Keep new-draft tooltip anchored to its trigger button
- Fix minimal-mode worktree/group header text truncation
- Tune minimal-mode right padding to reduce early label clipping

* fix: render reasoning through markdown pipeline

- Use Streamdown rendering for reasoning in live chat mode
- Remove italic styling from reasoning text
- Render expanded reasoning content with MarkdownRenderer

* chore: remove legacy electron dependencies

- Removed unused Electron packages from root and UI manifests
- Deleted obsolete Electron context menu type declaration
- Regenerated lockfile after dependency cleanup

* fix: handle non-repository folders in git status API

- Prevent 500 errors when status is requested outside a valid Git repo
- Improve repository detection using `git rev-parse --git-dir`
- Reduce noisy server logs for expected non-repo status checks

* fix unloaded session chat layout flicker

* fix: reduce noisy TTS status polling

Cache and dedupe TTS status requests, and only check provider availability when the related voice features are enabled so disabled voice setups stay quiet.

* perf: throttle background PR git status refreshes

* fix: improve VS Code Explorer file drop mentions in chat

- Add Explorer context action to insert selected files as @mentions.
- Handle Explorer drag-and-drop to prefill @file mentions instead of attachments.
- Prevent duplicate plain-path text when dropping multiple files.

* fix: deduplicate recent sessions in VS Code sidebar

- Hide sessions from main list when already shown in recent
- Apply dedup only in VS Code runtime
- Keep session search behavior unchanged

* feat: add true HMR dev flow for VS Code extension

- Load VS Code webview from Vite dev server with React refresh preamble
- Add `vscode:dev` runner that starts watchers and opens Extension Development Host
- Update VS Code dev docs and scripts to use the new HMR startup flow

* feat: polish VS Code session sidebar and attachment UX

- Add resizable sessions sidebar in VS Code layout
- Tighten session list spacing and hover behavior in VS Code
- Remove bulk file/image attach success toasts while keeping error toasts

packages/ui/src/components/chat/message/MessageBody.tsx

@@ -1186,16 +1186,16 @@ const AssistantMessageBody: React.FC<Omit<MessageBodyProps, 'isUser'>> = ({
                             />
                         );
                     } else {
-                        const partText = (part as { text?: string }).text;
-                        if (partText && partText.trim().length > 0) {
-                            rendered.push(
-                                <FadeInOnReveal key={`reasoning-${messageId}-${i}`}>
-                                    <div className="my-0.5 text-sm text-muted-foreground/60 italic leading-relaxed whitespace-pre-wrap">
-                                        {partText}
-                                    </div>
-                                </FadeInOnReveal>
-                            );
-                        }
+                        rendered.push(
+                            <AssistantTextPart
+                                key={`reasoning-${messageId}-${i}`}
+                                part={part}
+                                messageId={messageId}
+                                streamPhase={streamPhase}
+                                chatRenderMode={chatRenderMode}
+                                onContentChange={onContentChange}
+                            />
+                        );
                     }
                 }
                 i++;

packages/ui/src/components/chat/message/parts/ReasoningPart.tsx

@@ -7,6 +7,7 @@ import type { ContentChangeReason } from '@/hooks/useChatScrollManager';
 import { ScrollableOverlay } from '@/components/ui/ScrollableOverlay';
 import { useUIStore } from '@/stores/useUIStore';
 import { useDurationTickerNow } from './useDurationTicker';
+import { MarkdownRenderer } from '../../MarkdownRenderer';
 
 type PartWithText = Part & { text?: string; content?: string; time?: { start?: number; end?: number } };
 
@@ -78,6 +79,7 @@ type ReasoningTimelineBlockProps = {
     blockId: string;
     time?: { start?: number; end?: number };
     showDuration?: boolean;
+    isStreaming?: boolean;
 };
 
 export const ReasoningTimelineBlock: React.FC<ReasoningTimelineBlockProps> = ({
@@ -87,6 +89,7 @@ export const ReasoningTimelineBlock: React.FC<ReasoningTimelineBlockProps> = ({
     blockId,
     time,
     showDuration = true,
+    isStreaming = false,
 }) => {
     const [isExpanded, setIsExpanded] = React.useState(false);
 
@@ -140,7 +143,7 @@ export const ReasoningTimelineBlock: React.FC<ReasoningTimelineBlockProps> = ({
 
                 {(summary || (showDuration && typeof timeStart === 'number')) ? (
                     <div className="flex items-center gap-1 flex-1 min-w-0 typography-meta text-muted-foreground/70">
-                        {summary ? <span className="flex-1 min-w-0 truncate italic">{summary}</span> : null}
+                        {summary ? <span className="flex-1 min-w-0 truncate">{summary}</span> : null}
                         {showDuration && typeof timeStart === 'number' ? (
                             <span className="relative flex-shrink-0 tabular-nums text-right">
                                 <span className="text-muted-foreground/80 transition-opacity duration-150">
@@ -163,11 +166,17 @@ export const ReasoningTimelineBlock: React.FC<ReasoningTimelineBlockProps> = ({
                     )}
                 >
                     <ScrollableOverlay
-                        as="blockquote"
+                        as="div"
                         outerClassName="max-h-80"
-                        className="whitespace-pre-wrap break-words typography-meta italic text-muted-foreground/70 p-0"
+                        className="p-0"
                     >
-                        {text}
+                        <MarkdownRenderer
+                            content={text}
+                            messageId={blockId}
+                            isAnimated={false}
+                            isStreaming={isStreaming}
+                            variant="reasoning"
+                        />
                     </ScrollableOverlay>
                 </div>
             )}
@@ -191,6 +200,7 @@ const ReasoningPart: React.FC<ReasoningPartProps> = ({
     const rawText = partWithText.text || partWithText.content || '';
     const textContent = React.useMemo(() => cleanReasoningText(rawText), [rawText]);
     const time = partWithText.time;
+    const isStreaming = chatRenderMode === 'live' && typeof time?.end !== 'number';
 
     // Show reasoning even if time.end isn't set yet (during streaming)
     // Only hide if there's no text content
@@ -206,6 +216,7 @@ const ReasoningPart: React.FC<ReasoningPartProps> = ({
             blockId={part.id || `${messageId}-reasoning`}
             time={time}
             showDuration={chatRenderMode !== 'sorted'}
+            isStreaming={isStreaming}
         />
     );
 };