fix(explore-3d): tighten default 3D filter to tutorial + mission (#2517)

app/explore/src/App.vue

@@ -29,7 +29,7 @@ useTelemetry({ payload })
 // ---------------------------------------------------------------------------
 
 /** High-signal "spine" node types used as the default 3D filter subset. */
-const THREED_DEFAULT_TYPES: NodeType[] = ['tutorial', 'concept', 'mission']
+const THREED_DEFAULT_TYPES: NodeType[] = ['tutorial', 'mission']
 
 /** Whether the 3D toggle is visible: flag on AND desktop-only. */
 const show3dToggle = computed(() => !!payload.value?.features?.threeD && !isMobile.value)

app/explore/src/__tests__/App.test.ts

@@ -128,14 +128,14 @@ describe('App.vue — 2D/3D toggle visibility', () => {
     expect(wrapper.findAll('.explore__viewbtn').length).toBe(0)
   })
 
-  it('case D: clicking 3D button when filters are all-on narrows enabledNodeTypes to THREED_DEFAULT_TYPES (size 3)', async () => {
+  it('case D: clicking 3D button when filters are all-on narrows enabledNodeTypes to THREED_DEFAULT_TYPES (size 2)', async () => {
     _resetFilters()
     const { enabledNodeTypes } = useFilters()
     const wrapper = await mountApp({ threeD: true, mobile: false })
 
     // Filters should start at all-on
     const allOnSize = enabledNodeTypes.value.size
-    expect(allOnSize).toBeGreaterThan(3)
+    expect(allOnSize).toBeGreaterThan(2)
 
     // Click the 3D button
     const btns = wrapper.findAll('.explore__viewbtn')
@@ -146,11 +146,11 @@ describe('App.vue — 2D/3D toggle visibility', () => {
     await btn3d!.trigger('click')
     await nextTick()
 
-    // Should have narrowed to tutorial, concept, mission = 3 types
-    expect(enabledNodeTypes.value.size).toBe(3)
+    // Should have narrowed to tutorial, mission = 2 types
+    expect(enabledNodeTypes.value.size).toBe(2)
     expect(enabledNodeTypes.value.has('tutorial')).toBe(true)
-    expect(enabledNodeTypes.value.has('concept')).toBe(true)
     expect(enabledNodeTypes.value.has('mission')).toBe(true)
+    expect(enabledNodeTypes.value.has('concept')).toBe(false)
   })
 
   it('case E: 2D→3D→2D round-trip clears pathNodeIds (stale overlay fix)', async () => {

docs/superpowers/specs/2026-09-27-2517-explore-3d-graph-design.md

@@ -75,9 +75,11 @@ single-flight guard, fails to empty maps).
   toggle never renders ⇒ 3D chunk never downloads.
 
 **Default filtering (hairball fix):** on first switch to 3D, apply a **default node-type subset**
-instead of all 27 filters: **`tutorial + concept + mission`** (high-signal spine), everything else
-opt-in via the existing filter dropdown. Kept as a single named constant for easy tuning. The 2D
-view's all-on default is unchanged.
+instead of all 27 filters: **`tutorial + mission`** (~3,125 nodes, ~50% of the graph; missions
+supply the connective tissue since tutorials have no direct tutorial↔tutorial edges — they link
+through concepts/missions). Everything else — including `concept` — is opt-in via the existing
+filter dropdown. Kept as a single named constant for easy tuning. The 2D view's all-on default is
+unchanged.
 
 ### §4 — Bundle budget + testing