Feedback submission backlog

Declares the Inbox's change-feed watcher standing: it wakes every Feedback submission still waiting for its hand-over, including ones nobody ever read back.

• Purpose: Lists every Feedback/Feedback record mesh-wide and wakes, one at a time, each submission whose own hub still has to move it into Feedback/_Submissions or hand it to triage. Creating a node does not activate its hub, so without this an agent-filed report nobody reads back waits forever.
• Triggers: Portal start: the first frame of the synced query is the whole backlog, Change feed: a Feedback submission created or flipped to New
• Runs on: every portal with the Feedback package (held awake by the package's declared anchor, Feedback/Inbox)
• Wired: yes
• Queue path: Feedback/Inbox
• Doc path: Feedback/Guide
• Note: No model runs here. The watcher only activates records; each record's own hub moves it and stamps handedOverAt, which is what makes a re-activation a no-op. A record still waiting after FeedbackBacklog.SettleBudget is logged by path under [Feedback] and retried on the Inbox's next activation.