Fix: child tasks only from spec/breakdown agents; live review badge

Two fixes from real usage:
- Child-task creation is now gated to story-producing skills (spec-writing,
  story-breakdown). A code/design/test agent's output is the artifact — a numbered list
  in it (e.g. file names from an engineer) is no longer mistaken for child stories.
- The review-inbox badge now updates without a refresh: it polls more often (6s),
  refetches on window focus, and reacts to a REVIEWS_CHANGED event the board fires after
  Run (with a couple of delayed pulses to catch the ~5s completion) and the review page
  fires after approve / send back.

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

client/src/pages/ReviewsPage.tsx

@@ -8,6 +8,7 @@ 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 { REVIEWS_CHANGED } from '@/components/AppShell'
 import { AgentFace } from '@/components/AgentFace'
 import { MarkdownEditor } from '@/components/MarkdownEditor'
 import { api } from '@/lib/api'
@@ -169,6 +170,7 @@ function ReviewCard({ item, onDecided }: { item: ReviewItem; onDecided: (id: str
         toast.info('Sent back to the agent')
       }
       onDecided(item.id)
+      window.dispatchEvent(new Event(REVIEWS_CHANGED))
     } catch (err) {
       toast.error((err as Error).message)
     } finally {