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/ext_keys.h

@@ -1,4 +1,3 @@
-#include "core/namespaces.h"
 #pragma once
 // ext_keys — the SINGLE SOURCE OF TRUTH for the "reasampler" project ext-state
 // namespace + key names, shared by the extension (writer, via persist.h) and the
@@ -27,7 +26,7 @@ namespace reasampler {
 // because the value is fixed by the channel bit at build time. This is the wire-contract
 // reconciliation between S4 (shared ext_keys) and V4 (channel-isolated namespace): without
 // it a beta instrument would read the stable namespace and see empty state.
-inline const char* kProjExtNamespace() { return extStateNamespace().c_str(); }
+inline const char* kProjExtNamespace() { return version::extStateNamespace().c_str(); }
 
 // The multi-bank key: the whole serialized BankBook (pool + named banks). This is
 // the key the VST3 instrument reads to see the live bank (read-only, S4). persist.h