feat: host detail page + FM host context

Add /hosts/:id detail page with unified timeline (HostEvents + FMs + Repairs
+ part arrivals/departures) and a deployed-parts table. Hosts list rows now
link to the page. FM list + detail surface inline State/Stack badges next
to the asset ID, with the asset ID linking to the host page.

HostEvent audit model added; create/update in the hosts service now diff
and log state, stack, and field changes the same way parts.ts does.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/lib/queryKeys.ts

@@ -48,6 +48,8 @@ export const queryKeys = {
       [...queryKeys.hosts.all, 'list', filters ?? {}] as const,
     detail: (id: string) => [...queryKeys.hosts.all, 'detail', id] as const,
     deployedParts: (id: string) => [...queryKeys.hosts.all, 'deployed-parts', id] as const,
+    timeline: (id: string, filters?: Record<string, unknown>) =>
+      [...queryKeys.hosts.all, 'timeline', id, filters ?? {}] as const,
   },
   fms: {
     all: ['fms'] as const,