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/capture/render_settings.h

@@ -262,4 +262,4 @@ struct CaptureActionDef {
 // capture applies is read from the docked-panel setting, not baked into the row.
 const std::vector<CaptureActionDef>& captureActionTable();
 
-} // namespace reasampler::capture
+} // namespace reasampler::capture