fix: guard filter tail NaNs, skip static-filter envelope work, pin stereo filter path, correct stale comments

Codec fallback for non-finite filter fields, a modAmount==0 early-out in tickFilterCutoff,
new stereo render tests for the dual-mono mirror, and comment/test accuracy fixes flagged
in review (stale deck-width claims, restated invariants, drifted CMake link comments).

src/shell/instrument/editor_controls.cpp

@@ -1,8 +1,8 @@
 // editor_controls.cpp — the ReaSamplerEditor's parameter plumbing: the band-stack layout
 // resolve every paint/hit-test path shares, the control-value domain maps (controlValue /
-// applyControl — seconds/fraction/frames <-> normalized 0..1), the knob-deck group
-// descriptors + control-id<->value binding, and the envelope pack/unpack (the trigger-seam
-// converter). Value logic only — no painting, no window plumbing.
+// applyControl — seconds/fraction/frames <-> normalized 0..1), the control-id<->value binding
+// against the pure `deck_groups` module's descriptors, and the envelope pack/unpack (the
+// trigger-seam converter). Value logic only — no painting, no window plumbing.
 
 #include "shell/instrument/reasampler_editor.h"
 

src/shell/instrument/editor_session.cpp

@@ -38,8 +38,9 @@ using util::readFileBytes;
 
 ReaSamplerEditor::ReaSamplerEditor(ReaSamplerProcessor* processor)
     : CPluginView(nullptr), processor_(processor) {
-    // Default view size, tuned to the three band heights: chrome + two-lane waveform +
-    // deck row. 840x620 clears the full face without scroll on 1080p.
+    // Default view size, tuned to the band heights: chrome + two-lane waveform + the deck
+    // (now two rows since the filter group). 840x620 clears the full face without scroll on
+    // 1080p.
     ViewRect r(0, 0, 840, 620);
     setRect(r);
 }