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/wire/instrument_drop.h

@@ -3,7 +3,7 @@
 //
 // PURE MODULE (CLAUDE.md §load-bearing split): NO REAPER types, NO SWELL, NO VST3 SDK,
 // NO vendor/ includes. Standard library only (+ the pure sample_map it reuses and the
-// SDK-free UID macros in vst/reasampler_uid.h). Unit-tested outside the DAW — the same
+// SDK-free UID macros in core/wire/reasampler_uid.h). Unit-tested outside the DAW — the same
 // "small pure builder + round-trip proof" pattern as assignment_request / provenance.
 //
 // -- What it is (the S17 seam, extension side) --------------------------------
@@ -43,7 +43,7 @@ namespace reasampler::wire {
 // header carries (public.sdk vstpresetfile: "ASCII-encoded FUID"). On both COM-compatible
 // (Windows GUID byte order) and plain layouts, FUID::toString reduces to the four
 // INLINE_UID uint32 words printed "%08X" in order, so this derivation is platform-stable.
-// Sourced from the FROZEN macros in vst/reasampler_uid.h (the same constants the factory
+// Sourced from the FROZEN macros in core/wire/reasampler_uid.h (the same constants the factory
 // registers), channel-selected by the one REASAMPLER_CHANNEL_IS_BETA bit — a beta extension
 // writes presets only the beta VST class accepts, preserving the S18 pairing invariant.
 std::string vstClassIdHex();
@@ -111,4 +111,4 @@ bool infoNamesFxHotspot(const std::string& info);
 // its setState expects. Not called by the shell (which uses the .vstpreset image).
 std::vector<std::uint8_t> instrumentDropStateBytes(const std::string& sampleId);
 
-}  // namespace reasampler::wire
+}  // namespace reasampler::wire