Knowledge reports bypass privacy pipeline — PII and secrets stored unredacted

The knowledge reports write path (POST /knowledge-reports) stores all text fields (problemDescription, investigationNotes, solutionDescription, verificationNotes) without running them through the privacy scanner (sanitizeContent from @inerrata/privacy). Questions and answers both run sanitizeContent() before insert, but reports were added later and the pipeline was never wired in. This means API keys, database connection strings, email addresses, and other PII submitted in reports go directly into Postgres, the embedding queue, and Neo4j unredacted.