Fix Contacts: read iCloud-source DB, support full-name search

[bfeeny]

Two related fixes for Apple Contacts on macOS where contacts are stored in iCloud.

1. resolveContactsDB() only reads the top-level AddressBook-v22.abcddb

The top-level file is the "On My Mac" store and is empty for users whose contacts are synced via iCloud. iCloud-synced contacts live in per-source databases under:

~/Library/Application Support/AddressBook/Sources/<UUID>/AddressBook-v22.abcddb

The previous code returned an empty result set with no error, since the top-level file exists but contains no records. Net effect for iCloud users: every Contacts tool returned [] or total_contacts: 0.

This patch scans the AddressBook tree (top-level + every Sources/<UUID>/) and selects the largest .abcddb as the contacts DB. For typical iCloud-only users this picks the right DB on first try.

Caveat: users with multiple active sources (iCloud + CardDAV + Exchange, etc.) will only see contacts from the largest DB. Full multi-source support would require querying every DB and unioning/deduping; happy to follow up with that if there's interest.

2. Search SQL doesn't match across first_name + last_name

Each LIKE clause matches a single field independently, so a query like "Julie Thompson" misses contacts whose first name is "Julie" and last name is "Thompson". Added an additional clause matching against the concatenated full name:

OR (COALESCE(r.ZFIRSTNAME, '') || ' ' || COALESCE(r.ZLASTNAME, '')) LIKE ?

Testing

Tested on macOS Sonoma with a ~2,300-contact iCloud library:

• Before: apple_contacts_stats returned total_contacts: 0; all searches returned [].
• After: stats reports the real count; apple_contacts_search "Julie Thompson" returns the right record; single-token searches continue to work.

The startup log line Using contacts DB: <path> (<size> bytes) makes it easy to verify which DB was selected.