architecture v2: integrate codex review — major design changes

Key changes from codex critique:
- e2-medium (4GB) not e2-small — Claude Code needs 4GB+ RAM
- CLAUDE.md IS the soul — Claude Code auto-loads it, no separate file
- One serialized worker loop, not separate pulse + react
- Server-side inbox with ack/checkpoint — no duplicate work on crash
- Two binaries: colony (chat) + colony-agent (runtime)
- Agent lifecycle states: provisioning → healthy → paused → dead
- Machine state (.colony-state.json) separate from Claude memory
- Pin Claude Code version on agent VMs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/colony/src/components/MessageItem.tsx

@@ -8,6 +8,7 @@ import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@/comp
 interface Props {
   message: Message;
   compact?: boolean;
+  lastInGroup?: boolean;
   replyTarget?: Message;
   onSelect: (id: string) => void;
   onDelete: (channelId: string, msgId: string) => void;
@@ -73,7 +74,7 @@ function userHue(username: string): number {
   return Math.abs(hash) % 360;
 }
 
-export function MessageItem({ message, compact, replyTarget, onSelect, onDelete, onRestore, currentUsername, selected }: Props) {
+export function MessageItem({ message, compact, lastInGroup, replyTarget, onSelect, onDelete, onRestore, currentUsername, selected }: Props) {
   const [metaOpen, setMetaOpen] = useState(false);
   const isAgent = message.user.role === "agent";
   const isDeleted = !!message.deleted_at;