fix(toggles): keep toggle negatives in the Assembler's preview layering (#383)

The Assembler's injector layer no longer clears a toggle's own negative from the preview.

src/extension/graph.test.ts

@@ -277,6 +277,23 @@ describe("collectUpstreamProducers", () => {
     });
   });
 
+  it("collectUpstreamInjectorNegatives: a toggle's own negative, or null when it has none", () => {
+    const rows = [
+      { id: "a", kind: "toggle", name: "Rain", var: "rain", on: true, pin: false, out: 0, style: "switch", value: "in the rain", negative: "sunny sky" },
+      { id: "b", kind: "toggle", name: "Fog", var: "fog", on: false, pin: false, out: 0, style: "switch", off_negative: "clear air" },
+      { id: "c", kind: "toggle", name: "Wind", var: "wind", on: true, pin: false, out: 0, style: "switch" },
+    ];
+    const tg: LiteNodeLike = {
+      id: 1,
+      type: "WP_Toggles",
+      outputs: [{ name: "context", links: [100], type: "PIPELINE_CONTEXT" }],
+      widgets: [{ name: "wp_toggles", value: JSON.stringify({ version: 1, mode: "any", group_var: "", rows }) }],
+    };
+    const pov = ctxWriting(2, "Other", "unused", 100);
+    const g = chain([tg, pov], { 100: { origin_id: 1, target_id: 2 } });
+    expect(collectUpstreamInjectorNegatives(g, pov)).toEqual({ rain: "sunny sky", fog: "clear air", wind: null });
+  });
+
   it("attributes the loop's iteration vars, including the _total pair", () => {
     const loop: LiteNodeLike = {
       id: 1,

src/extension/graph.ts

@@ -19,7 +19,7 @@ import {
   cacheVersion as previewCacheVersion,
 } from "./preview-resolver";
 import { assignCodenames, baseCodename } from "./node-codename";
-import { TOGGLES_NODE, staticToggleInternals, staticToggleValues, togglesPreviewModules } from "./toggles";
+import { TOGGLES_NODE, staticToggleInternals, staticToggleNegatives, staticToggleValues, togglesPreviewModules } from "./toggles";
 import { MODEL_INFO_NODE, MODEL_VARS, internalModelVars, modelInfoPreviewModules, staticModelValues } from "./model-info";
 import { clauseActions, derivationTargets, evalConditionTree, isNegativeMode } from "./derivation-conditions";
 import type { SeedStrategy } from "../components/shared/seed-derive";
@@ -760,7 +760,8 @@ export function collectUpstreamInjectorNegatives(
       continue;
     }
     if (n.type === TOGGLES_NODE && !isSkippedMode(n)) {
-      for (const v of Object.keys(staticToggleValues(n))) out[v] = null;
+      // A write replaces the variable's negatives with the toggle's own.
+      for (const [v, neg] of Object.entries(staticToggleNegatives(n))) out[v] = neg || null;
       continue;
     }
     if (n.type !== "WP_ContextInjector" || isSkippedMode(n)) continue;

src/extension/toggles.ts

@@ -574,6 +574,19 @@ export function staticToggleValues(node: TogglesNodeLike): Record<string, string
   return resolveToggles(nodeTogglesConfig(node));
 }
 
+/** Each variable the node writes → the negative it carries now ("" for none):
+ *  its Negative while on, Off negative while off, and the pick's negative on
+ *  the Pick one variable. */
+export function staticToggleNegatives(node: TogglesNodeLike): Record<string, string> {
+  const cfg = nodeTogglesConfig(node);
+  const own = ownToggleNegatives(cfg);
+  const picked = pickedToggleNegative(cfg);
+  if (picked && cfg.group_var) own[cfg.group_var] = picked;
+  const out: Record<string, string> = {};
+  for (const v of Object.keys(resolveToggles(cfg))) out[v] = own[v] ?? "";
+  return out;
+}
+
 /** The node's variables that stay out of the prompt (graph walkers). */
 export function staticToggleInternals(node: TogglesNodeLike): Set<string> {
   return internalToggleVars(nodeTogglesConfig(node));