Profiles may inherit from another config file (extends: <path>): the
first profile of the referenced file is merged underneath (scalars from
the overlay win, slices concatenate base-first and de-duplicate, chains
resolve recursively, cycles are detected).
esbuild.excludeEntryPoints removes merged entry points by glob (** spans
path separators, * stays within a segment), applied after path
resolution so patterns and entries match in the same shape.
Lets product editions/flavors (e.g. the wmd4x Range Trader Pro edition)
build only their own entry set on top of a shared, merge-clean base
config. Includes unit tests and template docs.