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/shell/capture/capture.h

@@ -1,5 +1,5 @@
-#include "core/namespaces.h"
 #pragma once
+#include "core/namespaces.h"
 // capture — the REAPER-facing capture shell (CLAUDE.md §load-bearing split).
 //
 // This header declares the capture *seam* the later milestones fill:

src/shell/capture/insert.h

@@ -1,5 +1,5 @@
-#include "core/namespaces.h"
 #pragma once
+#include "core/namespaces.h"
 // insert — placement of bank samples into the arrange (M6). REAPER-facing shell:
 // it reads the bank_panel's current selection, resolves each selected sample's
 // file, and drops it into the arrange at the edit cursor via InsertMedia, wrapped

src/shell/capture/item_read.h

@@ -1,5 +1,5 @@
-#include "core/namespaces.h"
 #pragma once
+#include "core/namespaces.h"
 // item_read — the ONE place a MediaItem* is read for its canonical GUID string and for
 // the durable P_LANENAME of the fixed lane it sits on. Before this seam, view.cpp and
 // bank_panel.cpp each carried a near-identical private itemGuid / itemLaneName pair

src/shell/capture/provenance_shell.h

@@ -1,5 +1,5 @@
-#include "core/namespaces.h"
 #pragma once
+#include "core/namespaces.h"
 // provenance_shell — the REAPER-facing reads Milestone 10 needs, in one place.
 //
 // The PURE provenance module (provenance.h) owns the fingerprint encoding, the

src/shell/capture/track_guid.h

@@ -1,5 +1,5 @@
-#include "core/namespaces.h"
 #pragma once
+#include "core/namespaces.h"
 // track_guid — the ONE place a MediaTrack* is formatted into the canonical GUID
 // string used as a membership-index key. Both the Design View shell (view.cpp) and
 // the actions layer (actions.cpp) key membership on this exact string, so the key