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.
Width becomes a one-rung step from the control's natural fraction,
and invariants bound the ladder. The grant's free text is renamed
to GrantNote, and both grant ledgers show it as a muted note line.
cgalo5758