Add a "grab → move → drop" gesture that moves an existing positive
example's output to a new input position, preserving the output. This is
the new core's home for upstream InterfaceRL's drag-store/reposition-commit,
distinct from Explore→Place (which places newly-auditioned scratchpad sounds).
- nisps/ml/feedback.hpp: begin_reposition()/commit_reposition()/repositioning().
Reuses the Placing state (static_output holds the carried vector) but a
reposition_ flag makes commit AND the mode-switch teardown SKIP the weight
restore — the real net is never set aside here, so restoring snapshot_ would
clobber the live trained net. Guards cancel_place + abort_explore_place.
- firmware glue: state-gate Toggle B. Exploring → reroll/nudge (unchanged);
Idle → MomB1 grab, MomB2 drop (commit + add_example + train). The 4D variant
has no joystick button, so the gesture lives on the momentary toggle. Also
fix a stale top-of-file control-map comment that contradicted the bindings.
- tests: 4 reposition cases (hold without snapshot; commit stores carried
output with no restore; mode-switch aborts without clobber; begin-only-Idle).
- MAP.md: document the full ExploreAndPlace lifecycle + reposition wiring.
Audio-hold (carrying the sound audibly during the move) remains the existing
unwired static_output() TODO and affects Explore→Place identically.
Firmware compile unverified (no arduino-cli); host tests + lint pass.
