feat(mnemosyne): trust-based crystal rendering (#1166)

Wire crystal visual properties to fact trust scores:
- Trust > 0.8: bright glow, full opacity
- Trust 0.5-0.8: medium glow, 80% opacity
- Trust < 0.5: dim, 40% opacity
- Trust < 0.3: near-invisible, pulsing red

Adds:
- _getTrustVisuals() helper computes material props from trust
- updateMemoryVisual() for runtime trust updates
- trust persisted in exportIndex and localStorage
- Low-trust crystals pulse red in update() loop

Closes #1166

nexus/components/spatial-memory.js

@@ -140,6 +140,47 @@ const SpatialMemory = (() => {
     return new THREE.OctahedronGeometry(size, 0);
   }
 
+  // ─── TRUST-BASED VISUALS ─────────────────────────────
+  // Wire crystal visual properties to fact trust score (0.0-1.0).
+  // Issue #1166: Trust > 0.8 = bright glow/full opacity,
+  // 0.5-0.8 = medium/80%, < 0.5 = dim/40%, < 0.3 = near-invisible pulsing red.
+  function _getTrustVisuals(trust, regionColor) {
+    const t = Math.max(0, Math.min(1, trust));
+    if (t >= 0.8) {
+      return {
+        opacity: 1.0,
+        emissiveIntensity: 2.0 * t,
+        emissiveColor: regionColor,
+        lightIntensity: 1.2,
+        glowDesc: 'high'
+      };
+    } else if (t >= 0.5) {
+      return {
+        opacity: 0.8,
+        emissiveIntensity: 1.2 * t,
+        emissiveColor: regionColor,
+        lightIntensity: 0.6,
+        glowDesc: 'medium'
+      };
+    } else if (t >= 0.3) {
+      return {
+        opacity: 0.4,
+        emissiveIntensity: 0.5 * t,
+        emissiveColor: regionColor,
+        lightIntensity: 0.2,
+        glowDesc: 'dim'
+      };
+    } else {
+      return {
+        opacity: 0.15,
+        emissiveIntensity: 0.3,
+        emissiveColor: 0xff2200,
+        lightIntensity: 0.1,
+        glowDesc: 'untrusted'
+      };
+    }
+  }
+
   // ─── REGION MARKER ───────────────────────────────────
   function createRegionMarker(regionKey, region) {
     const cx = region.center[0];
@@ -216,17 +257,20 @@ const SpatialMemory = (() => {
     const region = REGIONS[mem.category] || REGIONS.working;
     const pos = mem.position || _assignPosition(mem.category, mem.id);
     const strength = Math.max(0.05, Math.min(1, mem.strength != null ? mem.strength : 0.7));
+    const trust = mem.trust != null ? Math.max(0, Math.min(1, mem.trust)) : 0.7;
     const size = 0.2 + strength * 0.3;
 
+    const tv = _getTrustVisuals(trust, region.color);
+
     const geo = createCrystalGeometry(size);
     const mat = new THREE.MeshStandardMaterial({
       color: region.color,
-      emissive: region.color,
+      emissive: tv.emissiveColor,
-      emissiveIntensity: 1.5 * strength,
+      emissiveIntensity: tv.emissiveIntensity,
       metalness: 0.6,
       roughness: 0.15,
       transparent: true,
-      opacity: 0.5 + strength * 0.4
+      opacity: tv.opacity
     });
 
     const crystal = new THREE.Mesh(geo, mat);
@@ -239,10 +283,12 @@ const SpatialMemory = (() => {
       region: mem.category,
       pulse: Math.random() * Math.PI * 2,
       strength: strength,
+      trust: trust,
+      glowDesc: tv.glowDesc,
       createdAt: mem.timestamp || new Date().toISOString()
     };
 
-    const light = new THREE.PointLight(region.color, 0.8 * strength, 5);
+    const light = new THREE.PointLight(tv.emissiveColor, tv.lightIntensity, 5);
     crystal.add(light);
 
     _scene.add(crystal);
@@ -337,8 +383,16 @@ const SpatialMemory = (() => {
       mesh.scale.setScalar(pulse);
 
       if (mesh.material) {
+        const trust = mesh.userData.trust != null ? mesh.userData.trust : 0.7;
         const base = mesh.userData.strength || 0.7;
-        mesh.material.emissiveIntensity = 1.0 + Math.sin(mesh.userData.pulse * 0.7) * 0.5 * base;
+        if (trust < 0.3) {
+          // Low trust: pulsing red — visible warning
+          const pulseAlpha = 0.15 + Math.sin(mesh.userData.pulse * 2.0) * 0.15;
+          mesh.material.emissiveIntensity = 0.3 + Math.sin(mesh.userData.pulse * 2.0) * 0.3;
+          mesh.material.opacity = pulseAlpha;
+        } else {
+          mesh.material.emissiveIntensity = 1.0 + Math.sin(mesh.userData.pulse * 0.7) * 0.5 * base;
+        }
       }
     });
 
@@ -368,6 +422,42 @@ const SpatialMemory = (() => {
     return REGIONS;
   }
 
+  // ─── UPDATE VISUAL PROPERTIES ────────────────────────
+  // Re-render crystal when trust/strength change (no position move).
+  function updateMemoryVisual(memId, updates) {
+    const obj = _memoryObjects[memId];
+    if (!obj) return false;
+
+    const mesh = obj.mesh;
+    const region = REGIONS[obj.region] || REGIONS.working;
+
+    if (updates.trust != null) {
+      const trust = Math.max(0, Math.min(1, updates.trust));
+      mesh.userData.trust = trust;
+      obj.data.trust = trust;
+      const tv = _getTrustVisuals(trust, region.color);
+      mesh.material.emissive = new THREE.Color(tv.emissiveColor);
+      mesh.material.emissiveIntensity = tv.emissiveIntensity;
+      mesh.material.opacity = tv.opacity;
+      mesh.userData.glowDesc = tv.glowDesc;
+      if (mesh.children.length > 0 && mesh.children[0].isPointLight) {
+        mesh.children[0].intensity = tv.lightIntensity;
+        mesh.children[0].color = new THREE.Color(tv.emissiveColor);
+      }
+    }
+
+    if (updates.strength != null) {
+      const strength = Math.max(0.05, Math.min(1, updates.strength));
+      mesh.userData.strength = strength;
+      obj.data.strength = strength;
+    }
+
+    _dirty = true;
+    saveToStorage();
+    console.info('[Mnemosyne] Visual updated:', memId, 'trust:', mesh.userData.trust, 'glow:', mesh.userData.glowDesc);
+    return true;
+  }
+
   // ─── QUERY ───────────────────────────────────────────
   function getMemoryAtPosition(position, maxDist) {
     maxDist = maxDist || 2;
@@ -507,6 +597,7 @@ const SpatialMemory = (() => {
         source: o.data.source || 'unknown',
         timestamp: o.data.timestamp || o.mesh.userData.createdAt,
         strength: o.mesh.userData.strength || 0.7,
+        trust: o.mesh.userData.trust != null ? o.mesh.userData.trust : 0.7,
         connections: o.data.connections || []
       }))
     };
@@ -653,7 +744,7 @@ const SpatialMemory = (() => {
   }
 
   return {
-    init, placeMemory, removeMemory, update,
+    init, placeMemory, removeMemory, update, updateMemoryVisual,
     getMemoryAtPosition, getRegionAtPosition, getMemoriesInRegion, getAllMemories,
     getCrystalMeshes, getMemoryFromMesh, highlightMemory, clearHighlight, getSelectedId,
     exportIndex, importIndex, searchNearby, REGIONS,