-- Node kind and OS columns (v0.6 P01, REQ-049).
-- Nullable for backward compatibility: existing rows get NULL, which
-- the Go scanNode helper maps to "" (empty string). New rows from
-- `orca init` get kind='localhost', os=<detected>; proxmox joins get
-- kind='proxmox', os='pve'.
ALTER TABLE nodes ADD COLUMN kind TEXT;
ALTER TABLE nodes ADD COLUMN os TEXT;

CREATE INDEX IF NOT EXISTS idx_nodes_kind ON nodes(kind);