refactor: improve virtualized text viewer with React Query infinite scroll and simplified buffering

backend/src/services/files.ts

@@ -274,36 +274,24 @@ function getMimeType(filePath: string): AllowedMimeType {
   return mimeTypes[ext] || 'text/plain'
 }
 
-async function countFileLines(filePath: string): Promise<number> {
-  return new Promise((resolve, reject) => {
-    let lineCount = 0
-    const stream = createReadStream(filePath, { encoding: 'utf8' })
-    const rl = createInterface({ input: stream, crlfDelay: Infinity })
-
-    rl.on('line', () => { lineCount++ })
-    rl.on('close', () => resolve(lineCount))
-    rl.on('error', reject)
-  })
-}
-
-async function readFileLines(filePath: string, startLine: number, endLine: number): Promise<string[]> {
+async function readFileLinesAndCount(
+  filePath: string,
+  startLine: number,
+  endLine: number
+): Promise<{ lines: string[]; totalLines: number }> {
   return new Promise((resolve, reject) => {
     const lines: string[] = []
     let currentLine = 0
     const stream = createReadStream(filePath, { encoding: 'utf8' })
     const rl = createInterface({ input: stream, crlfDelay: Infinity })
-    
+
     rl.on('line', (line) => {
       if (currentLine >= startLine && currentLine < endLine) {
         lines.push(line)
       }
       currentLine++
-      if (currentLine >= endLine) {
-        rl.close()
-        stream.destroy()
-      }
     })
-    rl.on('close', () => resolve(lines))
+    rl.on('close', () => resolve({ lines, totalLines: currentLine }))
     rl.on('error', reject)
   })
 }
@@ -322,9 +310,8 @@ export async function getFileRange(userPath: string, startLine: number, endLine:
     throw { message: 'Path is a directory', statusCode: 400 }
   }
 
-  const totalLines = await countFileLines(validatedPath)
+  const { lines, totalLines } = await readFileLinesAndCount(validatedPath, startLine, endLine)
   const clampedEnd = Math.min(endLine, totalLines)
-  const lines = await readFileLines(validatedPath, startLine, clampedEnd)
   const mimeType = getMimeType(validatedPath)
 
   return {

frontend/src/components/file-browser/FilePreview.tsx

@@ -9,7 +9,7 @@ import { MarkdownRenderer } from './MarkdownRenderer'
 
 const API_BASE = API_BASE_URL
 
-const VIRTUALIZATION_THRESHOLD_BYTES = 8_000
+const VIRTUALIZATION_THRESHOLD_BYTES = 50_000
 const MARKDOWN_PREVIEW_SIZE_LIMIT = 1_000_000
 
 interface FilePreviewProps {

frontend/src/components/message/EditableUserMessage.tsx

@@ -89,7 +89,7 @@ export const EditableUserMessage = memo(function EditableUserMessage({
         onKeyDown={handleKeyDown}
         onFocus={() => setIsEditingMessage(true)}
         onBlur={() => setIsEditingMessage(false)}
-        className="w-full p-3 rounded-lg bg-background border border-primary/50 focus:border-primary focus:ring-1 focus:ring-primary outline-none resize-none min-h-[60px] text-sm"
+        className="w-full p-3 rounded-lg bg-background border border-primary/50 focus:border-primary focus:ring-1 focus:ring-primary outline-none resize-none min-h-[60px] text-[16px] md:text-sm"
         placeholder="Edit your message..."
         disabled={refreshMessage.isPending}
       />

frontend/src/components/model/ModelSelectDialog.tsx

@@ -57,7 +57,7 @@ function SearchInput({ onSearch, initialValue = "" }: SearchInputProps) {
           placeholder="Search models..."
           value={value}
           onChange={(e) => setValue(e.target.value)}
-          className="pl-10 text-sm"
+          className="pl-10 md:text-sm"
         />
       </div>
     </div>

frontend/src/components/repo/RepoMcpDialog.tsx

@@ -1,21 +1,17 @@
 import { useState, useEffect, useCallback } from 'react'
 import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription } from '@/components/ui/dialog'
 import { Switch } from '@/components/ui/switch'
+import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
-import { Loader2, XCircle, AlertCircle, Plug } from 'lucide-react'
-import { mcpApi, type McpStatus } from '@/api/mcp'
+import { DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuTrigger } from '@/components/ui/dropdown-menu'
+import { DeleteDialog } from '@/components/ui/delete-dialog'
+import { DropdownMenuSeparator } from '@/components/ui/dropdown-menu'
+import { Loader2, XCircle, AlertCircle, Plug, Shield, MoreVertical, Key, RefreshCw } from 'lucide-react'
+import { McpOAuthDialog } from '@/components/settings/McpOAuthDialog'
+import { mcpApi, type McpStatus, type McpServerConfig, type McpAuthStartResponse } from '@/api/mcp'
 import { useMutation } from '@tanstack/react-query'
 import { showToast } from '@/lib/toast'
 
-interface McpServerConfig {
-  type: 'local' | 'remote'
-  enabled?: boolean
-  command?: string[]
-  url?: string
-  environment?: Record<string, string>
-  timeout?: number
-}
-
 interface RepoMcpDialogProps {
   open: boolean
   onOpenChange: (open: boolean) => void
@@ -28,6 +24,8 @@ interface RepoMcpDialogProps {
 export function RepoMcpDialog({ open, onOpenChange, config, directory }: RepoMcpDialogProps) {
   const [localStatus, setLocalStatus] = useState<Record<string, McpStatus>>({})
   const [isLoadingStatus, setIsLoadingStatus] = useState(false)
+  const [removeAuthConfirmServer, setRemoveAuthConfirmServer] = useState<string | null>(null)
+  const [authDialogServerId, setAuthDialogServerId] = useState<string | null>(null)
 
   const mcpServers = config?.content?.mcp as Record<string, McpServerConfig> | undefined || {}
   const serverIds = Object.keys(mcpServers)
@@ -68,6 +66,40 @@ export function RepoMcpDialog({ open, onOpenChange, config, directory }: RepoMcp
       showToast.error(error instanceof Error ? error.message : 'Failed to update MCP server')
     },
   })
+
+  const removeAuthMutation = useMutation({
+    mutationFn: async (serverId: string) => {
+      if (!directory) throw new Error('No directory provided')
+      await mcpApi.removeAuthDirectory(serverId, directory)
+    },
+    onSuccess: async () => {
+      showToast.success('Authentication removed for this location')
+      setRemoveAuthConfirmServer(null)
+      await fetchStatus()
+    },
+    onError: (error) => {
+      showToast.error(error instanceof Error ? error.message : 'Failed to remove authentication')
+    },
+  })
+
+  const handleOAuthAutoAuth = async () => {
+    if (!authDialogServerId || !directory) return
+    await mcpApi.authenticateDirectory(authDialogServerId, directory)
+    await fetchStatus()
+    setAuthDialogServerId(null)
+  }
+
+  const handleOAuthStartAuth = async (): Promise<McpAuthStartResponse> => {
+    if (!authDialogServerId) throw new Error('No server ID')
+    return await mcpApi.startAuth(authDialogServerId)
+  }
+
+  const handleOAuthCompleteAuth = async (code: string) => {
+    if (!authDialogServerId) return
+    await mcpApi.completeAuth(authDialogServerId, code)
+    await fetchStatus()
+    setAuthDialogServerId(null)
+  }
 
   useEffect(() => {
     if (open && directory) {
@@ -156,7 +188,14 @@ export function RepoMcpDialog({ open, onOpenChange, config, directory }: RepoMcp
                 const serverConfig = mcpServers[serverId]
                 const status = localStatus[serverId]
                 const isConnected = status?.status === 'connected'
+                const needsAuth = status?.status === 'needs_auth'
                 const failed = status?.status === 'failed'
+                const isRemote = serverConfig.type === 'remote'
+                const hasOAuthConfig = isRemote && !!serverConfig.oauth
+                const hasOAuthError = failed && isRemote && /oauth|auth.*state/i.test(status.error)
+                const isOAuthServer = hasOAuthConfig || hasOAuthError || (needsAuth && isRemote)
+                const connectedWithOAuth = isOAuthServer && isConnected
+                const showAuthButton = needsAuth || (isOAuthServer && failed)
 
                 return (
                   <div
@@ -168,6 +207,11 @@ export function RepoMcpDialog({ open, onOpenChange, config, directory }: RepoMcp
                         <p className="text-sm font-medium truncate">
                           {getDisplayName(serverId)}
                         </p>
+                        {connectedWithOAuth && (
+                          <span title="OAuth authenticated">
+                            <Shield className="h-3 w-3 text-muted-foreground" />
+                          </span>
+                        )}
                         {getStatusBadge(status)}
                       </div>
                       <p className="text-xs text-muted-foreground truncate">
@@ -181,20 +225,94 @@ export function RepoMcpDialog({ open, onOpenChange, config, directory }: RepoMcp
                       )}
                     </div>
 
-                    <Switch
-                      checked={isConnected}
-                      disabled={toggleMutation.isPending}
-                      onCheckedChange={(enabled) => {
-                        toggleMutation.mutate({ serverId, enable: enabled })
-                      }}
-                      onClick={(e) => e.stopPropagation()}
-                    />
+                    <div className="flex items-center gap-2">
+                      {showAuthButton ? (
+                        <Button
+                          onClick={() => setAuthDialogServerId(serverId)}
+                          disabled={toggleMutation.isPending}
+                          variant="default"
+                          size="sm"
+                        >
+                          <Key className="h-3 w-3 mr-1" />
+                          Auth
+                        </Button>
+                      ) : (
+                        <Switch
+                          checked={isConnected}
+                          disabled={toggleMutation.isPending || removeAuthMutation.isPending}
+                          onCheckedChange={(enabled) => {
+                            toggleMutation.mutate({ serverId, enable: enabled })
+                          }}
+                          onClick={(e) => e.stopPropagation()}
+                        />
+                      )}
+                      {(isOAuthServer || needsAuth) && (
+                        <DropdownMenu>
+                          <DropdownMenuTrigger asChild>
+                            <Button variant="ghost" size="sm" className="h-8 w-8 p-0">
+                              <MoreVertical className="h-4 w-4" />
+                            </Button>
+                          </DropdownMenuTrigger>
+                          <DropdownMenuContent align="end">
+                            {showAuthButton && (
+                              <DropdownMenuItem onClick={() => setAuthDialogServerId(serverId)}>
+                                <Key className="h-4 w-4 mr-2" />
+                                Authenticate
+                              </DropdownMenuItem>
+                            )}
+                            {connectedWithOAuth && (
+                              <DropdownMenuItem onClick={() => setAuthDialogServerId(serverId)}>
+                                <RefreshCw className="h-4 w-4 mr-2" />
+                                Re-authenticate
+                              </DropdownMenuItem>
+                            )}
+                            {connectedWithOAuth && (
+                              <>
+                                <DropdownMenuSeparator />
+                                <DropdownMenuItem
+                                  onClick={() => setRemoveAuthConfirmServer(serverId)}
+                                  disabled={removeAuthMutation.isPending}
+                                >
+                                  <Shield className="h-4 w-4 mr-2" />
+                                  {removeAuthMutation.isPending ? 'Removing...' : 'Remove Auth'}
+                                </DropdownMenuItem>
+                              </>
+                            )}
+                          </DropdownMenuContent>
+                        </DropdownMenu>
+                      )}
+                    </div>
                   </div>
                 )
               })}
             </div>
           )}
         </div>
+
+        <DeleteDialog
+          open={!!removeAuthConfirmServer}
+          onOpenChange={() => setRemoveAuthConfirmServer(null)}
+          onConfirm={() => {
+            if (removeAuthConfirmServer) {
+              removeAuthMutation.mutate(removeAuthConfirmServer)
+            }
+          }}
+          onCancel={() => setRemoveAuthConfirmServer(null)}
+          title="Remove Authentication"
+          description="This will remove the OAuth credentials for this MCP server at this location. You will need to re-authenticate to use this server here again."
+          itemName={removeAuthConfirmServer ? getDisplayName(removeAuthConfirmServer) : ''}
+          isDeleting={removeAuthMutation.isPending}
+        />
+
+        <McpOAuthDialog
+          open={!!authDialogServerId}
+          onOpenChange={(o) => !o && setAuthDialogServerId(null)}
+          serverName={authDialogServerId || ''}
+          onAutoAuth={handleOAuthAutoAuth}
+          onStartAuth={handleOAuthStartAuth}
+          onCompleteAuth={handleOAuthCompleteAuth}
+          directory={directory}
+        />
       </DialogContent>
     </Dialog>
   )

frontend/src/components/session/QuestionPrompt.tsx

@@ -435,7 +435,7 @@ function QuestionStep({
               value={customInput}
               onChange={(e) => onCustomInputChange(e.target.value)}
               placeholder="Type your own answer..."
-              className="min-h-[60px] sm:min-h-[80px] text-xs sm:text-sm resize-none border-blue-500/30 focus:border-blue-500"
+              className="min-h-[60px] sm:min-h-[80px] text-[16px] sm:text-xs md:text-sm resize-none border-blue-500/30 focus:border-blue-500"
               onKeyDown={(e) => {
                 if (e.key === 'Enter' && !e.shiftKey) {
                   e.preventDefault()

frontend/src/components/settings/AccountSettings.tsx

@@ -163,11 +163,11 @@ export function AccountSettings() {
               <div className="space-y-3 sm:space-y-4">
                 <div className="space-y-1.5">
                   <Label className="text-xs sm:text-sm">Name</Label>
-                  <Input value={user.name} disabled className="h-9 sm:h-10 text-sm" />
+                  <Input value={user.name} disabled className="h-9 sm:h-10 md:text-sm" />
                 </div>
                 <div className="space-y-1.5">
                   <Label className="text-xs sm:text-sm">Email</Label>
-                  <Input value={user.email} disabled className="h-9 sm:h-10 text-sm" />
+                  <Input value={user.email} disabled className="h-9 sm:h-10 md:text-sm" />
                 </div>
                 <Button variant="outline" onClick={() => setEditingProfile(false)} className="h-9 sm:h-10">
                   Done
@@ -216,7 +216,7 @@ export function AccountSettings() {
                     value={currentPassword}
                     onChange={(e) => setCurrentPassword(e.target.value)}
                     placeholder="Enter current password"
-                    className="h-9 sm:h-10 text-sm"
+                    className="h-9 sm:h-10 md:text-sm"
                   />
                 </div>
                 <div className="space-y-1.5">
@@ -227,7 +227,7 @@ export function AccountSettings() {
                     value={newPassword}
                     onChange={(e) => setNewPassword(e.target.value)}
                     placeholder="At least 8 characters"
-                    className="h-9 sm:h-10 text-sm"
+                    className="h-9 sm:h-10 md:text-sm"
                   />
                 </div>
                 <div className="flex gap-2">
@@ -271,7 +271,7 @@ export function AccountSettings() {
               placeholder="Passkey name (optional)"
               value={passkeyName}
               onChange={(e) => setPasskeyName(e.target.value)}
-              className="h-9 sm:h-10 text-sm"
+              className="h-9 sm:h-10 md:text-sm"
             />
             <Button 
               onClick={handleAddPasskey}