Close pass four: undetented host curve read, LiveValues guard, ordering assert, static-lane fix, docs

Points toPlain's exponent arm at the undetented curve map so host reads
match the editor; adds a sizeof guard plus field-poison test for
LiveValues::operator==; skips the model write when an automation value
hasn't moved; corrects five stale doc citations.

tests/test_param_format.cpp

@@ -126,11 +126,10 @@ static void testTheEditorAndTheHostPrintTheSameDigitsAtTheSameStoredValue() {
     }
 }
 
-// The one place the two surfaces GENUINELY diverge, asserted so it stays a known property rather
-// than a surprise: an exponent inside curve_law's centre detent but not exactly neutral is
-// reachable only through an overlay knot drag, and the host — which holds the norm and nothing
-// else — reads it back as the neutral the knob law snaps to.
-static void testAnOffDetentExponentReadsNeutralToTheHostAndTrueToTheEditor() {
+// A continuous range stays continuous at the host boundary (Daniel, 2026-08-02): the knob
+// detent is a drag affordance only, so an exponent inside it but not exactly neutral — reachable
+// via an overlay knot drag — must read back true to the host, the same digits the editor shows.
+static void testAnOffDetentExponentReadsTrueToBothTheHostAndTheEditor() {
     PlaySeconds play;
     // The detent is +/-0.01 in NORM, which is a ~+/-0.047 band in the exponent — so 1.04 is
     // inside it and still prints as a distinct number.
@@ -144,7 +143,7 @@ static void testAnOffDetentExponentReadsNeutralToTheHostAndTrueToTheEditor() {
     char hostBuf[24];
     formatPlainFor(DeckParam::kAttackCurve, toPlain(DeckParam::kAttackCurve, hostNorm), hostBuf,
                    sizeof(hostBuf));
-    CHECK(std::string(hostBuf) == "1.00");
+    CHECK(std::string(hostBuf) == "1.04");
 }
 
 static void testKeyTrackPrintsTheSameDigitsFromEitherSurface() {
@@ -227,7 +226,7 @@ static void testEveryExposedParameterHasAFormatterThatWritesSomething() {
 int main() {
     testEachCategoryPrintsItsSpecifiedShape();
     testTheEditorAndTheHostPrintTheSameDigitsAtTheSameStoredValue();
-    testAnOffDetentExponentReadsNeutralToTheHostAndTrueToTheEditor();
+    testAnOffDetentExponentReadsTrueToBothTheHostAndTheEditor();
     testMasterGainPrintsTheSameDigitsFromEitherSurface();
     testKeyTrackPrintsTheSameDigitsFromEitherSurface();
     testTypingBackADisplayedValueLandsOnIt();