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/client-bundle.spec.ts

@@ -59,7 +59,7 @@ describe('tsdown client artifact', () => {
     const { handoff, surface } = await loadArtifact()
     expect(handoff.id).toBe(PLUGIN_ID)
     expect(surface.apply).toBeTypeOf('function')
-    expect(surface.inject).toEqual(['slots'])
+    expect(surface.inject).toEqual(['slots', 'conversation'])
   })
 
   it.skipIf(code === undefined)('mounted as an object plugin, apply registers both view tabs on the real ring', async () => {
@@ -71,6 +71,10 @@ describe('tsdown client artifact', () => {
       name: 'root',
       children: { 'conversation.view': { kind: 'list', scope: 'session' } },
     }, (_p: { renderSlot?: unknown }) => null)
+    // The plugin injects 'conversation' as an ordering edge (the declaring
+    // plugin provides it after declaring the ring); the bench declares the
+    // ring itself, so a stub satisfies the wait.
+    ctx.provide('conversation', {})
     const fiber = ctx.plugin(surface as { apply: (ctx: Context) => void })
     await fiber.await()
     expect(slots.entries('conversation.view').map(e => e.options.id)).toEqual(['trajectory', 'waterfall'])