feat(odin): use the full page (full width + taller shell)

Drop the 1100px max-width cap and size the chat shell to fill the content
area (100dvh - 100px = top bar + main bottom padding), so Odin uses the whole
page now that it owns the route.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/components/odin/OdinChat.tsx

@@ -373,7 +373,7 @@ export default function OdinChat() {
   return (
     <Box
       sx={{
-        height: "calc(100dvh - 140px)",
+        height: "calc(100dvh - 100px)",
         display: "flex",
         flexDirection: "column",
         gap: 1.5,