Cloud review (/code-review ultra) fails consistently on large repo: "all review agents terminated before completing"

## Description

`/code-review ultra ` (ultrareview) fails identically on back-to-back runs against a large private monorepo. Both cloud sessions end with:

> Cloud review failed: orchestrator reported an error: Review failed: all review agents terminated before completing. See session logs for details.

No findings are produced. Two of three free ultrareview runs were consumed by these failures.

## Context that suggests a size-related, deterministic failure

- Running local `/ultrareview` in the same repo is refused with "Repo is too large. Push a PR and use `/code-review ultra ` instead." — but the recommended cloud path then dies too, so large repos currently have no working ultra path.
- Repo `.git` is ~414 MB.
- Target PR: 110 changed files, +5056/−2026.
- Failure reproduced twice with identical error text (2026-08-21 and 2026-08-22), which does not look transient.

## Sessions (for internal log lookup)

- session_01VuarTMpNToivmz9Td4mdnZ
- session_01QRDTNfYSH2YyMKomF9xMri

## Environment

- Claude Code CLI 2.1.226, macOS (Darwin 25.6.0)
- Launched from terminal in a git worktree of the repo; GitHub connection freshly re-established via `/web-setup` before the runs

## Expected

Cloud review completes (or fails with an actionable message — e.g. "repo/PR too large for cloud review" — before consuming a metered run).

## Actual

All review agents terminate before completing; run is consumed; no findings.

Start with the `/code-review ultra ` and local `/ultrareview` entry points, then inspect the referenced session logs for the repeated termination on large repositories. Done means cloud review completes for the stated PR size or rejects it with an actionable size limit before consuming a run.

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