Add ScreenConnect-parity features (high + medium)

Viewer:
- Toolbar: Ctrl+Alt+Del, clipboard paste, monitor picker, file transfer, chat, WoL buttons
- Multi-monitor: agent sends monitor_list on connect, viewer can switch via dropdown
- Clipboard sync: agent polls local clipboard → sends to viewer; viewer paste → agent sets remote clipboard
- File transfer panel: drag-drop upload to agent, directory browser, download files from remote
- Chat panel: bidirectional text chat forwarded through relay

Agent:
- Multi-monitor capture with set_monitor/set_quality message handlers
- exec_key_combo for Ctrl+Alt+Del and arbitrary combos
- Clipboard polling via pyperclip (both directions)
- File upload/download/list_files with base64 chunked protocol
- Attended mode (--attended): zenity/kdialog/PowerShell consent dialog before accepting stream
- Auto-update: heartbeat checks version, downloads new binary and exec-replaces self (Linux)
- Reports MAC address on registration (for WoL)

Relay:
- Forwards monitor_list, clipboard_content, file_chunk, file_list, chat_message agent→viewer
- Session recording: when RECORDING_DIR env set, saves JPEG frames as .remrec files
- ALLOWED_ORIGINS CORS now set from NEXT_PUBLIC_APP_URL in docker-compose

Database:
- groups table (id, name, description, created_by)
- machines: group_id, mac_address, notes, tags text[]
- Migration 0003 applied

Dashboard:
- Machines page: search, tag filter, group filter, inline notes/tags/rename editing
- MachineCard: inline tag management, group picker, notes textarea
- Admin page: new Groups tab (create/list/delete groups)
- API: PATCH /api/machines/[id] (name, notes, tags, groupId)
- API: GET/POST/DELETE /api/groups
- API: POST /api/machines/wol (broadcast magic packet)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/machines/[id]/route.ts

@@ -4,6 +4,40 @@ import { machines } from '@/lib/db/schema'
 import { eq, and } from 'drizzle-orm'
 import { NextRequest, NextResponse } from 'next/server'
 
+export async function PATCH(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const session = await auth()
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+  }
+  const { id } = await params
+  const body = await request.json()
+
+  const updates: Record<string, unknown> = {}
+  if (body.name !== undefined) updates.name = String(body.name).slice(0, 255)
+  if (body.notes !== undefined) updates.notes = body.notes ? String(body.notes) : null
+  if (body.tags !== undefined) updates.tags = Array.isArray(body.tags) ? body.tags.map(String) : []
+  if (body.groupId !== undefined) updates.groupId = body.groupId || null
+
+  if (Object.keys(updates).length === 0) {
+    return NextResponse.json({ error: 'Nothing to update' }, { status: 400 })
+  }
+
+  const result = await db
+    .update(machines)
+    .set(updates)
+    .where(and(eq(machines.id, id), eq(machines.userId, session.user.id)))
+    .returning({ id: machines.id })
+
+  if (!result[0]) {
+    return NextResponse.json({ error: 'Not found' }, { status: 404 })
+  }
+
+  return NextResponse.json({ success: true })
+}
+
 export async function DELETE(
   _request: NextRequest,
   { params }: { params: Promise<{ id: string }> }