Q-W1 code-review follow-ups: restore 104 trailing newlines, relocate reasampler_uid.h to core/wire, drop ext_keys namespaces shim, add slot_map_tests, golden serialize literals for 4 modules, namespaces.h/pragma-once ordering sweep. 60/60 green.

src/core/ui/bank_grid.cpp

@@ -224,4 +224,4 @@ float compressAmplitudeForDisplay(float linear) {
     return linear < 0.0f ? -clamped : clamped;
 }
 
-} // namespace reasampler::ui
+} // namespace reasampler::ui