fix(gui): CI activation order + review-bot findings

The session-title snapshot exposed a real activation race: ui-trajectory
and ui-question register into conversation-declared slots but only
injected 'slots', so nothing ordered their applies after ui-conversation's
— register() into the undeclared slot threw and the entry FAILED. Both now
inject 'conversation' as an ordering edge (documented as such; specs stub
the service where the bench declares the slot itself).

Review-bot findings, all three applied: the module loader's load sink
cross-checks the handoff id against the arriving row (a mis-stamped bundle
can no longer register under another entry's identity); the default
execute seam removes the inline script node right after its synchronous
execution (repeated HMR rebuilds no longer accumulate dead nodes); a
throwing onRebuilt subscriber is contained per-listener and routed to
onError instead of escaping the fs.watchFile callback.

packages/client/ui-trajectory/tests/views.spec.tsx

@@ -83,6 +83,9 @@ async function bench() {
   const chatBody = vi.fn(() => <div data-testid="chat-body" />)
   slots.register(
     { name: 'conversation.view', id: 'chat', order: 0, label: 'Chat' } as never, chatBody as never)
+  // 'conversation' inject is an ordering edge; the bench declares the ring
+  // itself, so a stub satisfies the wait.
+  ctx.provide('conversation', {})
   const fiber = ctx.plugin({ inject: [...inject], apply })
   await fiber.await()
   return { ctx, slots, fiber }