Across-the-board rename so the unit prefix matches the repo
name (mb = msgbase). Brings naming into line with
fpc-ftn-transport's tt.* prefix and avoids the historical
"ma" abbreviation that meant nothing to new readers.
Files renamed via git mv:
src/ma.{api,events,kludge,lock,paths,types}.pas
-> src/mb.{...}.pas
src/formats/ma.fmt.{jam,squish,hudson,msg,pcboard,ezycom,
goldbase,wildcat,wcutil}{,.uni}.pas
-> src/formats/mb.fmt.*.pas
All `unit ma.X` declarations and `uses ma.X` clauses rewritten
to `mb.X` across src/, examples/, tests/.
Suite: 47/47 (read 7, hwm 11, lock 4, pack 4, write 5,
wildcat 5, consumer_round1 5, batch's gone w/ PKT relocation,
plus testutil).
Consumer impact: anyone with `uses ma.api;` etc. needs to
update to `uses mb.api;`. No semantic changes; a search/replace
on the consumer's source tree is the only migration step.
NR's notes (~/.MSGAPI_MSGS.md round 3) align this against
their already-pinned 8130b40; the next NR pin bump rolls in
both this rename and any further work in one step.