test: register the smoke link for the key-quantisation internals (#331)

smoke-select flagged quantizeKeyCoord/INCIDENT_EPS/KEY_FACTOR as symbols no
smoke names — true by design: the smoke proves the verdicts through the
rendered card, never touching the internals that decide which nodes are one
node. The registry entry records that non-textual link (#241 rule).

Issue: #331
User-Visible: no

scripts/smoke-links.mjs

@@ -27,6 +27,13 @@
 
 /** @type {SmokeLink[]} */
 export const SMOKE_LINKS = [
+  {
+    symbols: ['quantizeKeyCoord', 'INCIDENT_EPS', 'KEY_FACTOR'],
+    smokes: ['smoke_junction_limits.mjs'],
+    because: 'the smoke proves the write barrier verdicts (refusal toasts, resize stop, '
+      + 'fail-closed candidate) through the rendered card, never naming the key-quantisation '
+      + 'internals that decide which nodes are one node (#331 §2.1)',
+  },
   {
     symbols: [
       'placeResizeAreaLabel', 'resizeInwardNormal', 'resizeMeasuredEdges',