diff --git a/scripts/steiger-rules.ts b/scripts/steiger-rules.ts
index 4cddfd8bb..a72a3731a 100644
--- a/scripts/steiger-rules.ts
+++ b/scripts/steiger-rules.ts
@@ -201,8 +201,8 @@ const strictTestFilePlacement = createFileRule('open-pencil/strict-test-file-pla
   if (sourceRel.startsWith('tests/engine/')) {
     if (sourceRel.endsWith('.test.ts')) return null
     if (sourceRel.endsWith('/helpers.ts') || sourceRel.endsWith('.bench.ts')) return null
-    if (path.basename(sourceRel).startsWith('visual-')) return null
-    return 'Engine/unit tests must live under tests/engine/** and use *.test.ts; helpers.ts, *.bench.ts, and visual-* support scripts are allowed.'
+    if (/\/visual\/[^/]+\.ts$/.test(sourceRel)) return null
+    return 'Engine/unit tests must live under tests/engine/** and use *.test.ts; helpers.ts, *.bench.ts, and domain visual support scripts are allowed.'
   }
   if (sourceRel.startsWith('tests/helpers/')) return null
   return 'Tests must live under tests/e2e/** (*.spec.ts), tests/engine/** (*.test.ts), or tests/helpers/**.'
@@ -239,8 +239,13 @@ const noMisplacedEngineTestDomainPaths = createFileRule(
   'open-pencil/no-misplaced-engine-test-domain-paths',
   (sourceRel) => {
     const redirect = ENGINE_TEST_DOMAIN_REDIRECTS.find(({ from }) => sourceRel.startsWith(from))
-    if (!redirect) return null
-    return `Move tests from ${redirect.from} under ${redirect.to} to mirror ${redirect.source}.`
+    if (redirect) {
+      return `Move tests from ${redirect.from} under ${redirect.to} to mirror ${redirect.source}.`
+    }
+    if (/^tests\/engine\/[^/]+\.test\.ts$/.test(sourceRel)) {
+      return 'Move root-level engine tests under a domain folder that mirrors the source module under test.'
+    }
+    return null
   }
 )
 
diff --git a/tests/engine/color.test.ts b/tests/engine/color/basic.test.ts
similarity index 100%
rename from tests/engine/color.test.ts
rename to tests/engine/color/basic.test.ts
diff --git a/tests/engine/okhcl.test.ts b/tests/engine/color/okhcl/basic.test.ts
similarity index 100%
rename from tests/engine/okhcl.test.ts
rename to tests/engine/color/okhcl/basic.test.ts
diff --git a/tests/engine/geometry.test.ts b/tests/engine/geometry/basic.test.ts
similarity index 100%
rename from tests/engine/geometry.test.ts
rename to tests/engine/geometry/basic.test.ts
diff --git a/tests/engine/matrix.test.ts b/tests/engine/geometry/matrix.test.ts
similarity index 100%
rename from tests/engine/matrix.test.ts
rename to tests/engine/geometry/matrix.test.ts
diff --git a/tests/engine/iconify.test.ts b/tests/engine/icons/iconify.test.ts
similarity index 100%
rename from tests/engine/iconify.test.ts
rename to tests/engine/icons/iconify.test.ts
diff --git a/tests/engine/image.test.ts b/tests/engine/images/basic.test.ts
similarity index 100%
rename from tests/engine/image.test.ts
rename to tests/engine/images/basic.test.ts
diff --git a/tests/engine/lint.test.ts b/tests/engine/lint/basic.test.ts
similarity index 100%
rename from tests/engine/lint.test.ts
rename to tests/engine/lint/basic.test.ts
diff --git a/tests/engine/mcp.test.ts b/tests/engine/mcp/tools.test.ts
similarity index 100%
rename from tests/engine/mcp.test.ts
rename to tests/engine/mcp/tools.test.ts
diff --git a/tests/engine/profiler.test.ts b/tests/engine/profiler/basic.test.ts
similarity index 100%
rename from tests/engine/profiler.test.ts
rename to tests/engine/profiler/basic.test.ts
diff --git a/tests/engine/random.test.ts b/tests/engine/random/basic.test.ts
similarity index 100%
rename from tests/engine/random.test.ts
rename to tests/engine/random/basic.test.ts
diff --git a/tests/engine/render/canvas/silhouette-autopsy.test.ts b/tests/engine/render/canvas/silhouette-autopsy.test.ts
index 097120a84..8162b57a4 100644
--- a/tests/engine/render/canvas/silhouette-autopsy.test.ts
+++ b/tests/engine/render/canvas/silhouette-autopsy.test.ts
@@ -291,8 +291,8 @@ describe('Doc 02 — Formula Deconstruction: Static Code Claims', () => {
 // ============================================================
 
 describe('Doc 03 — Artifact Analysis: Static + Runtime Verification', () => {
-  test('C03-01: visual-inner-shadow-counter.ts exists and checks for right-edge shadow', () => {
-    const visualTestPath = repoTestPath('engine/visual-inner-shadow-counter.ts')
+  test('C03-01: render visual inner-shadow counter script exists and checks for right-edge shadow', () => {
+    const visualTestPath = repoTestPath('engine/render/canvas/visual/inner-shadow-counter.ts')
     const src = readFileSync(visualTestPath, 'utf-8')
     expect(src).toContain('hasShadowOnRightInnerEdge')
     expect(src).toContain("t.color === 'black'")
diff --git a/tests/engine/visual-inner-shadow-counter.ts b/tests/engine/render/canvas/visual/inner-shadow-counter.ts
similarity index 97%
rename from tests/engine/visual-inner-shadow-counter.ts
rename to tests/engine/render/canvas/visual/inner-shadow-counter.ts
index 1ec48ee35..0d049d696 100644
--- a/tests/engine/visual-inner-shadow-counter.ts
+++ b/tests/engine/render/canvas/visual/inner-shadow-counter.ts
@@ -101,7 +101,7 @@ async function main() {
     }
   }
 
-  console.log('Transitions at centerY:', transitions)
+  console.warn('Transitions at centerY:', transitions)
 
   // Expected transitions for a physically correct inner shadow (light from left):
   // 1. blue -> black (left outer edge, shadow starts)
@@ -120,7 +120,7 @@ async function main() {
   const data = image.encodeToBytes(ck.ImageFormat.PNG, 100)
   if (data) {
     await Bun.write('scratch/escher-trap-detected.png', data)
-    console.log('Saved scratch/escher-trap-detected.png')
+    console.warn('Saved scratch/escher-trap-detected.png')
   }
   surface.delete()
 
@@ -131,7 +131,7 @@ async function main() {
     )
     process.exit(1)
   } else {
-    console.log(
+    console.warn(
       '✅ PASSED: Physically accurate shadow detected on the right inner edge of the counter'
     )
     process.exit(0)
diff --git a/tests/engine/visual-sdf-test-matrix.ts b/tests/engine/render/canvas/visual/sdf-test-matrix.ts
similarity index 97%
rename from tests/engine/visual-sdf-test-matrix.ts
rename to tests/engine/render/canvas/visual/sdf-test-matrix.ts
index f305ea43b..965ed4fd4 100644
--- a/tests/engine/visual-sdf-test-matrix.ts
+++ b/tests/engine/render/canvas/visual/sdf-test-matrix.ts
@@ -160,7 +160,7 @@ async function main() {
   await mkdir(outputDir, { recursive: true })
 
   const matrix = generateMatrix()
-  console.log(`Generated ${matrix.length} test cases`)
+  console.warn(`Generated ${matrix.length} test cases`)
 
   let generated = 0
   let failed = 0
@@ -234,7 +234,7 @@ async function main() {
     renderer.destroy()
   }
 
-  console.log(`\nResult: ${generated} generated, ${failed} failed out of ${matrix.length}`)
+  console.warn(`\nResult: ${generated} generated, ${failed} failed out of ${matrix.length}`)
 }
 
 main()
diff --git a/tests/engine/visual-verify-text-inner-shadow.ts b/tests/engine/render/canvas/visual/verify-text-inner-shadow.ts
similarity index 87%
rename from tests/engine/visual-verify-text-inner-shadow.ts
rename to tests/engine/render/canvas/visual/verify-text-inner-shadow.ts
index 383b1644f..fcf227708 100644
--- a/tests/engine/visual-verify-text-inner-shadow.ts
+++ b/tests/engine/render/canvas/visual/verify-text-inner-shadow.ts
@@ -19,7 +19,7 @@ async function main() {
 
   // Load Inter font from public dir
   const fontPath = join(process.cwd(), 'public/Inter-SemiBold.ttf')
-  console.log('Loading font from:', fontPath)
+  console.warn('Loading font from:', fontPath)
   const fontData = await readFile(fontPath)
   fontManager.markLoaded(
     'Inter',
@@ -62,9 +62,9 @@ async function main() {
   renderer.fontProvider = fontProvider
   renderer.fontsLoaded = true
 
-  console.log('Node created:', nodeId)
-  console.log('Font loaded for node:', renderer.isNodeFontLoaded(textNode))
-  console.log('Absolute position:', graph.getAbsolutePosition(nodeId))
+  console.warn('Node created:', nodeId)
+  console.warn('Font loaded for node:', renderer.isNodeFontLoaded(textNode))
+  console.warn('Absolute position:', graph.getAbsolutePosition(nodeId))
 
   // Render with scale 2
   const data = renderNodesToImage(ck, renderer, graph, pageId, [nodeId], {
@@ -75,7 +75,7 @@ async function main() {
   surface.delete()
 
   if (data && data.length > 2000) {
-    console.log(`✅ Generated scratch/text-inner-shadow-verification.png (${data.length} bytes)`)
+    console.warn(`✅ Generated scratch/text-inner-shadow-verification.png (${data.length} bytes)`)
   } else {
     console.error(`❌ Failed to generate useful image (size: ${data?.length ?? 0} bytes)`)
     if (data) {
diff --git a/tests/engine/copy.test.ts b/tests/engine/scene-graph/copy.test.ts
similarity index 100%
rename from tests/engine/copy.test.ts
rename to tests/engine/scene-graph/copy.test.ts
diff --git a/tests/engine/mutation.test.ts b/tests/engine/scene-graph/mutation.test.ts
similarity index 100%
rename from tests/engine/mutation.test.ts
rename to tests/engine/scene-graph/mutation.test.ts
diff --git a/tests/engine/snap.test.ts b/tests/engine/snap/basic.test.ts
similarity index 100%
rename from tests/engine/snap.test.ts
rename to tests/engine/snap/basic.test.ts
diff --git a/tests/engine/xpath.test.ts b/tests/engine/tools/xpath/basic.test.ts
similarity index 100%
rename from tests/engine/xpath.test.ts
rename to tests/engine/tools/xpath/basic.test.ts
diff --git a/tests/engine/vector.test.ts b/tests/engine/vector/basic.test.ts
similarity index 100%
rename from tests/engine/vector.test.ts
rename to tests/engine/vector/basic.test.ts
diff --git a/tests/engine/centerline.test.ts b/tests/engine/vector/centerline.test.ts
similarity index 100%
rename from tests/engine/centerline.test.ts
rename to tests/engine/vector/centerline.test.ts