chore(deps): resolve RUSTSEC-2025-0134 — rustls-pemfile is unmaintained

[bug-ops]

Summary

Security advisory RUSTSEC-2025-0134 detected:

• Crate: rustls-pemfile v2.2.0 is unmaintained (archived Aug 2025)
• Current dependency chain: zeph → zeph-mcp → qdrant-client v1.17.0 → tonic v0.12.3 → rustls-pemfile
• Recommendation: Migrate to rustls-pki-types (1.9.0+) using PemObject trait

Impact

• Qdrant integration (memory backend) affected transitively
• No immediate security vulnerability, but unmaintained status means no future patches

Action Items

• Check if qdrant-client has a newer version with updated rustls dependencies
• If not available, file issue with qdrant-client or migrate to alternative Qdrant client
• Update dependency when available
• Re-run cargo deny check advisories to verify resolution

References

• Advisory: https://rustsec.org/advisories/RUSTSEC-2025-0134
• Announcement: Archived - please see rustls-pki-types instead rustls/pemfile#61