The handoff doc was the starting point for this session's controller
work — a list of open questions about getting a Joy-Con working on the
Samsung Fold 6 via the 8BitDo adapter. Those questions have been
answered (the working path is PS-Classic mode) and the adapter approach
is being replaced entirely by a DIY ESP32 bridge. Move the doc into
docs/ so it's not sitting at the repo root, rename it to reflect that
it's archaeology rather than an active handoff, and add a banner at
the top pointing at joycon-esp32-bridge.md for the current plan.
