v0.177.0

BREAKING CHANGE

• create_share / nc_share_create now reject a shareType=3
  (public link) call that also carries shareWith, and a recipient-typed call
  that omits it. Both combinations previously reached the server: the first
  silently produced an anonymous public link while reporting success, which is
  the defect being fixed. A caller relying on either now gets a ValueError /
  ToolError instead of a share. Recorded as breaking so it is discoverable by
  version rather than by surprise, even though the prior behaviour was wrong.

Feat

• client: wire the streaming path into DAV error typing too
• client: surface the DAV layer's own explanation on failure

Fix

• calendar: give CalDAV writes ETag concurrency control
• client: unblock the Sonar gate, keep the error message on one line
• client: avoid a self-referential cause, and test the wiring
• sharing: attach the public-link redirect only where it applies
• sharing: stop the rejection pointing agents at a nonexistent tool
• sharing: reject shareType/shareWith pairings that silently misfire

Refactor

• client: drop the dead logger, type request, sharpen the docstring

Perf

• calendar: close the last per-event ETag round trip
• calendar: batch the todo-listing ETag fetch
• calendar: ask the date-range REPORT for getetag