Add a search tool that finds contacts by free-text substring match
across the four fields users actually look at:
- full name (FN)
- nickname
- any email address
- any phone number (compared as digits-only so "+1 234-567-890"
matches a search for "2345678")
Without this tool, an MCP client that wants to "find John's email"
has to pull every contact via list_contacts and filter client-side,
which costs a CardDAV REPORT per addressbook even when the user only
has a single hit. Doing the filter server-side (still cheap — it
streams the full vcards but discards non-matches before serialising
the response) keeps the tool surface symmetric with the rest of the
contacts API: list, get, create, update, delete, *search*.
When ``addressbook`` is omitted the search spans every addressbook
the authenticated user can read.
License: AGPL-3.0, matching the project.
KuriGohan-Kamehameha
7974b67d4b