[Bug] Ultrareview crashes during dedupe step without delivering final report

Bug Description
Title:
Ultrareview crashed during dedupe step — free usage consumed despite no final report

Body:
## Summary
Ran /ultrareview on a branch (full-review → main). The verify step completed successfully (15 candidates → 12 confirmed, 3 refuted), but the run crashed at the dedupe step before producing a final
report. The local task notification reported "Review crashed before producing findings" even though findings were visible in the cloud session UI.

## Impact
This consumed one of my free ultrareview usages despite no final report being delivered. Requesting that the usage be credited back.

## Repro details

• Session ID: session_01CXxDytbGihRP4My3nwiRR1
• Session URL: https://claude.ai/code/session_01CXxDytbGihRP4My3nwiRR1
• Scope: 166 files changed, 75,014 insertions
• Branch: full-review → main

## What I observed

• Setup ✓
• Find: 15 candidates ✓
• Verify: 12 confirmed · 3 refuted ✓
• Dedupe: ✗ (crashed)
• Final report: not delivered to local session (only visible by reading raw findings in the cloud UI)

## Expected
Either (a) dedupe completes and a report is delivered, or (b) on crash, the partial verified findings are still surfaced to the local session, and the free-usage counter is not decremented.

## Ask
Please credit the free usage back, and let me know if any additional logs would help debug the dedupe crash.