Summary

compressed_context in the compression_failure_pairs SQLite table stores compaction summaries verbatim. If a conversation contained vault secrets, API keys, or PII that survived summarization, they would be stored in plaintext SQLite without applying the redact module or ContentSanitizer.

Mitigating Factors

• Data is summarized (not raw conversation)
• Feature is off by default (enabled = false)
• Cleanup bounds storage at 100 rows
• Database is local-only

Recommended Fix

Apply ContentSanitizer or the existing redact module to compressed_context before storing it in log_compression_failure().

File: crates/zeph-memory/src/sqlite/compression_guidelines.rs:84-103

Identified by code reviewer (REVIEW-6) during ACON compression guidelines PR (#1647) review.