Markdown Edit/Preview tabs + read-only .md viewer for skills & profiles

Adds MarkdownEditor (react-markdown + remark-gfm, no raw HTML — authored/retrieved
content is data, not markup) with Edit | Preview tabs, wired into the AGENTS.md and
SKILL.md editors, the agent persona, and the review artifact.

Adds a read-only "View" on every skill and agent-profile card — including builtins,
which previously had no way to be inspected at all — rendering the full SKILL.md /
AGENTS.md (frontmatter + body + actions/golden tests). Collapses a same-version
builtin that an org has forked so its own copy shadows it, keeping the version
picker unambiguous and the item clearly editable/versionable.

Also lands the agent-face wiring on the seat configurator (a live xl preview with a
state cycler) and the review inbox header.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/pages/ReviewsPage.tsx

@@ -8,6 +8,8 @@ import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
 import { Label } from '@/components/ui/label'
 import { Skeleton } from '@/components/ui/skeleton'
 import { Textarea } from '@/components/ui/textarea'
+import { AgentFace } from '@/components/AgentFace'
+import { MarkdownEditor } from '@/components/MarkdownEditor'
 import { api } from '@/lib/api'
 import { diffWords } from '@/lib/diff'
 import { useAuth } from '@/store/auth'
@@ -126,10 +128,8 @@ function ReviewCard({ item, onDecided }: { item: ReviewItem; onDecided: (id: str
   return (
     <Card>
       <CardHeader>
-        <div className="flex items-center gap-2">
-          <span className="grid size-8 shrink-0 place-items-center rounded-md bg-seat-ai font-semibold text-white">
-            AI
-          </span>
+        <div className="flex items-center gap-3">
+          <AgentFace size="md" monogram={item.agentId} state="review" className="shrink-0" />
           <div className="min-w-0 flex-1">
             <CardTitle className="truncate text-base">{item.title}</CardTitle>
             <div className="mt-1 flex items-center gap-2">
@@ -148,12 +148,12 @@ function ReviewCard({ item, onDecided }: { item: ReviewItem; onDecided: (id: str
       <CardContent className="flex flex-col gap-4">
         <div className="flex flex-col gap-2">
           <Label htmlFor={`content-${item.id}`}>Proposed artifact</Label>
-          <Textarea
+          <MarkdownEditor
             id={`content-${item.id}`}
             value={content}
-            onChange={(e) => setContent(e.target.value)}
+            onChange={setContent}
             rows={6}
-            className="font-mono text-xs"
+            mono
           />
         </div>