Adds 'aliases' parameter to create additional symlinks to wrapped executables.
This allows tools to be accessible under multiple names.

Downloads all files in parallel with aria2c while playing them sequentially with mpv.
Waits for each file to have content before starting playback.
Extracts basename from URLs since aria2c saves without directory structure.

- 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