feat(editor): add sidebar mode to CodeEditor component

Add an optional  prop to the CodeEditor component to support
rendering in both modal and sidebar layouts. When enabled, the editor
adapts its container styling and removes the fixed overlay positioning,
allowing it to be embedded inline. This includes conditional rendering
of the loading state and main container to properly display within a
sidebar context while maintaining the existing modal behavior as the
default.

src/components/MainContent.jsx

@@ -11,7 +11,7 @@
  * No session protection logic is implemented here - it's purely a props bridge.
  */
 
-import React, { useState, useEffect } from 'react';
+import React, { useState, useEffect, useRef } from 'react';
 import ChatInterface from './ChatInterface';
 import FileTree from './FileTree';
 import CodeEditor from './CodeEditor';
@@ -28,13 +28,13 @@ import { useTaskMaster } from '../contexts/TaskMasterContext';
 import { useTasksSettings } from '../contexts/TasksSettingsContext';
 import { api } from '../utils/api';
 
-function MainContent({ 
-  selectedProject, 
-  selectedSession, 
-  activeTab, 
-  setActiveTab, 
-  ws, 
-  sendMessage, 
+function MainContent({
+  selectedProject,
+  selectedSession,
+  activeTab,
+  setActiveTab,
+  ws,
+  sendMessage,
   messages,
   isMobile,
   isPWA,
@@ -61,6 +61,9 @@ function MainContent({
   const [editingFile, setEditingFile] = useState(null);
   const [selectedTask, setSelectedTask] = useState(null);
   const [showTaskDetail, setShowTaskDetail] = useState(false);
+  const [editorWidth, setEditorWidth] = useState(600);
+  const [isResizing, setIsResizing] = useState(false);
+  const resizeRef = useRef(null);
   
   // PRD Editor state
   const [showPRDEditor, setShowPRDEditor] = useState(false);
@@ -153,6 +156,52 @@ function MainContent({
     console.log('Update task status:', taskId, newStatus);
     refreshTasks?.();
   };
+
+  // Handle resize functionality
+  const handleMouseDown = (e) => {
+    if (isMobile) return; // Disable resize on mobile
+    setIsResizing(true);
+    e.preventDefault();
+  };
+
+  useEffect(() => {
+    const handleMouseMove = (e) => {
+      if (!isResizing) return;
+
+      const container = resizeRef.current?.parentElement;
+      if (!container) return;
+
+      const containerRect = container.getBoundingClientRect();
+      const newWidth = containerRect.right - e.clientX;
+
+      // Min width: 300px, Max width: 80% of container
+      const minWidth = 300;
+      const maxWidth = containerRect.width * 0.8;
+
+      if (newWidth >= minWidth && newWidth <= maxWidth) {
+        setEditorWidth(newWidth);
+      }
+    };
+
+    const handleMouseUp = () => {
+      setIsResizing(false);
+    };
+
+    if (isResizing) {
+      document.addEventListener('mousemove', handleMouseMove);
+      document.addEventListener('mouseup', handleMouseUp);
+      document.body.style.cursor = 'col-resize';
+      document.body.style.userSelect = 'none';
+    }
+
+    return () => {
+      document.removeEventListener('mousemove', handleMouseMove);
+      document.removeEventListener('mouseup', handleMouseUp);
+      document.body.style.cursor = '';
+      document.body.style.userSelect = '';
+    };
+  }, [isResizing]);
+
   if (isLoading) {
     return (
       <div className="h-full flex flex-col">
@@ -234,10 +283,10 @@ function MainContent({
   return (
     <div className="h-full flex flex-col">
       {/* Header with tabs */}
-      <div 
+      <div
         className="bg-white dark:bg-gray-800 border-b border-gray-200 dark:border-gray-700 p-3 sm:p-4 pwa-header-safe flex-shrink-0"
       >
-        <div className="flex items-center justify-between">
+        <div className="flex items-center justify-between relative">
           <div className="flex items-center space-x-2 sm:space-x-3">
             {isMobile && (
               <button
@@ -409,11 +458,13 @@ function MainContent({
         </div>
       </div>
 
-      {/* Content Area */}
-      <div className="flex-1 flex flex-col min-h-0 overflow-hidden">
-        <div className={`h-full ${activeTab === 'chat' ? 'block' : 'hidden'}`}>
-          <ErrorBoundary showDetails={true}>
-            <ChatInterface
+      {/* Content Area with Right Sidebar */}
+      <div className="flex-1 flex min-h-0 overflow-hidden">
+        {/* Main Content */}
+        <div className={`flex-1 flex flex-col min-h-0 overflow-hidden ${editingFile ? 'mr-0' : ''}`}>
+          <div className={`h-full ${activeTab === 'chat' ? 'block' : 'hidden'}`}>
+            <ErrorBoundary showDetails={true}>
+              <ChatInterface
               selectedProject={selectedProject}
               selectedSession={selectedSession}
               ws={ws}
@@ -513,14 +564,45 @@ function MainContent({
             onClearLogs={() => setServerLogs([])}
           /> */}
         </div>
+        </div>
+
+        {/* Code Editor Right Sidebar - Desktop only, Mobile uses modal */}
+        {editingFile && !isMobile && (
+          <>
+            {/* Resize Handle */}
+            <div
+              ref={resizeRef}
+              onMouseDown={handleMouseDown}
+              className="flex-shrink-0 w-1 bg-gray-200 dark:bg-gray-700 hover:bg-blue-500 dark:hover:bg-blue-600 cursor-col-resize transition-colors relative group"
+              title="Drag to resize"
+            >
+              {/* Visual indicator on hover */}
+              <div className="absolute inset-y-0 left-1/2 -translate-x-1/2 w-1 bg-blue-500 dark:bg-blue-600 opacity-0 group-hover:opacity-100 transition-opacity" />
+            </div>
+
+            {/* Editor Sidebar */}
+            <div
+              className="flex-shrink-0 border-l border-gray-200 dark:border-gray-700 h-full overflow-hidden"
+              style={{ width: `${editorWidth}px` }}
+            >
+              <CodeEditor
+                file={editingFile}
+                onClose={handleCloseEditor}
+                projectPath={selectedProject?.path}
+                isSidebar={true}
+              />
+            </div>
+          </>
+        )}
       </div>
 
-      {/* Code Editor Modal */}
-      {editingFile && (
+      {/* Code Editor Modal for Mobile */}
+      {editingFile && isMobile && (
         <CodeEditor
           file={editingFile}
           onClose={handleCloseEditor}
           projectPath={selectedProject?.path}
+          isSidebar={false}
         />
       )}