Add IDriverControl capability interface in Core.Abstractions with a
RebrowseAsync(IAddressSpaceBuilder, CancellationToken) hook so operators
can force a controller-side @tags re-walk without restarting the driver.
AbCipDriver now implements IDriverControl. RebrowseAsync clears the UDT
template cache (so stale shapes from a pre-download program don't
survive) then runs the same enumerator + builder fan-out as
DiscoverAsync, serialised against concurrent discovery / rebrowse via
a new SemaphoreSlim.
Driver.AbCip.Cli ships a `rebrowse` subcommand mirroring the existing
probe / read shape: connects to a single gateway, runs RebrowseAsync
against an in-memory builder, and prints discovered tag names so
operators can sanity-check the controller's symbol table from a shell.
Tests cover: two consecutive RebrowseAsync calls bump the enumerator's
Create / Enumerate counters once each, discovered tags reach the
supplied builder, the template cache is dropped on rebrowse, and the
driver exposes IDriverControl. 313 AbCip unit tests + 17 CLI tests +
37 Core.Abstractions tests pass.
Closes#233
