Recommendation history has high failed/degraded ratio

[simplerjiang]

• Source: .automation/buglist.md #50 and .automation/sprint.md V048-DEBT-14.
• Impact: Recommendation workflow reliability appears low to users.
• Repro:
  1. Open recommendation history.
  2. Count recent completed/degraded/failed sessions.
• Expected: Failures are rare or clearly attributed to dependency outages with recovery options.
• Actual: Historical note says recent 20 included 15 failed, 4 degraded, 1 completed.
• Claim: Assign recommendation/backend owner.
• Repair: Separate LLM instability from app failure; add retry/recovery where appropriate.
• Verification: Backend session tests and browser recommendation history check.