Introduce a commercial license option alongside AGPL-3.0-only, require a
CLA for contributors, and document the terms in COMMERCIAL.md and
NOTICE. Add a script to stamp SPDX headers on Go files and apply it
across the tree.
Parse every config value through a single declared type at save, boot,
and validate, and expose the settings seam from the terminal so
operators can list, set, clear, and validate overrides without SQL.
cgalo5758