- Remove identities file requirement
- Convert from writeShellApplication to makeWrapper
- Use PASS_BULK_KEY_FILE environment variable for bulk decryption
- Auto-create bulk key file from password store if needed
- Remove complex bulk operations logic

Fixes deployment error where syncthing was trying to reference machines (like mors)
that don't have syncthing IDs in the vars system.

- Update syncthing peer discovery to read from vars/per-machine//syncthing/syncthing.pub/value
- Update zerotier host discovery to read from vars/per-machine//zerotier/zerotier-ip/value
- Update syncthing key/cert references to use config.clan.core.vars.generators.syncthing.files paths