Report the instrument's automatable parameters to the host under a frozen id table, in signal-flow order, with real units

42 of 44 ids issued: pitch key-track and Trigger length stay reserved
pending a live path. Master gain reclassified Live — it never reloaded.

tests/test_deck_groups_state.cpp

@@ -40,6 +40,10 @@ static void testEveryDeckControlIsClassifiedIntoOneOfTheThreeCommitTiers() {
         DeckParam::kFilterEnvAttackCurve, DeckParam::kFilterEnvDecayCurve,
         DeckParam::kFilterEnvReleaseCurve,
         DeckParam::kFilterTrigAttackCurve, DeckParam::kFilterTrigDecayCurve,
+        // The one live control that does not ride the live block: a lock-free atomic the audio
+        // thread applies as a post-sum multiply. The tier answers "does an edit reach the audio
+        // without a reload", not "which mechanism carries it".
+        DeckParam::kMasterGain,
     };
     for (DeckParam p : live) CHECK(deckParamCommit(p) == LiveCommit::Live);
 
@@ -60,7 +64,7 @@ static void testEveryDeckControlIsClassifiedIntoOneOfTheThreeCommitTiers() {
         DeckParam::kAmpEnvSelect, DeckParam::kPitchEnvSelect, DeckParam::kFilterEnvSelect,
         DeckParam::kAmpEnvMode, DeckParam::kPitchEnvMode, DeckParam::kFilterEnvMode,
         DeckParam::kVoiceCount, DeckParam::kVoiceMode,
-        DeckParam::kMonoTrigger, DeckParam::kMasterGain, DeckParam::kLimiterEnable,
+        DeckParam::kMonoTrigger, DeckParam::kLimiterEnable,
         DeckParam::kMasterMeter, DeckParam::kMasterGr,
     };
     for (DeckParam p : reloads) CHECK(deckParamCommit(p) == LiveCommit::Reload);
@@ -96,7 +100,10 @@ static void testOnlyALiveControlsDragTakesTheLiveTier() {
     // it move a sounding note) nor as Reload (which would re-decode the WAV under a swept knob).
     CHECK(knob(DeckParam::kRate) == LiveCommit::NoteOnLatched);
     CHECK(knob(DeckParam::kTrigLength) == LiveCommit::Reload);
-    CHECK(knob(DeckParam::kMasterGain) == LiveCommit::Reload);
+    // Master gain is Live and reaches the audio BESIDE the live block rather than through it —
+    // one atomic the audio thread applies as a post-sum multiply. Classifying it Reload would
+    // claim a gain move re-decodes the WAV, which it never did.
+    CHECK(knob(DeckParam::kMasterGain) == LiveCommit::Live);
     CHECK(knob(DeckParam::kAmpEnvSelect) == LiveCommit::Reload);
     // The shell's processor-side sentinels (preview velocity is -2) and any out-of-range id
     // are not parameter-set controls, so they must never reach the enum.