v0.18.0

This release explicitly targets Hubuum server v0.0.20.
The server image, Rust 1.88 MSRV, and public feature combinations are unchanged.
Existing 0.17.0 callers need no migration.

Added

• Typed related-object filter groups for class object lists by ID or name in
  async and blocking clients. RelatedObjectFilter provides typed target-field
  predicates, exact class selectors, and bounded relationship depth. Query
  builders reject invalid aliases, duplicate groups, more than four groups, and
  invalid JSON paths before transport.

Changed

• Refresh compatible dependencies, updating smallvec to 1.16.4.