Read path is cgo like search. Control questions live in rank so CI can
test them without ladybug. Python bin/kb/{get,stats,eval} stays the
runner fallback.
bin/brain/serve.go (ladybug tags) calls internal/brain instead of exec.
HTTP tests inject a fake API so CI stays cgo-free. ExecSearcher remains
the fallback when the binary is built without system_ladybug.
Commands live at bin/brain/{index,get,stats,eval,watch}.go and
bin/mail/import.go, bin/markdown/import.go, bin/postgres/query.go.
Python remains the Ladybug write worker. index_mail is a deprecation
shim that rebuilds via --with-mail.
* feat(brain): HTTP serve from bin/brain/serve.go, default Go search binary.
Move the HTTP package to internal/httpapi. Default backend is
var/bin/brain-search, not Python. bin/serve.go stays as a deprecation shim.
* feat(httpapi): default search backend is var/bin/brain-search.
bin/brain/serve.go is the command; bin/serve.go stays as a tagged
deprecation shim. Tests fail if the default path still names Python.
Collapse nested kbsearch/chats go.mod into the root module. Ranking stays
cgo-free under internal/brain/rank so CI does not need ladybug. bin/kb/search
is a deprecation wrapper that still sets CGO and builds the binary.