docs: add captured Core Web Vitals results

.claude/skills/webperf-core-web-vitals/SKILL.md

@@ -241,4 +241,5 @@ When multiple CWV metrics are poor, prioritize investigation:
 ## References
 
 - `references/snippets.md` — Descriptions and thresholds for each script
-- `references/schema.md` — Return value schema for interpreting script output
+- `references/schema.md` — Return value schema for interpreting script output
+- `references/examples.json` — Captured return values used in the snippet pages

.claude/skills/webperf-core-web-vitals/references/examples.json

@@ -0,0 +1,220 @@
+{
+  "viewport": "desktop",
+  "waitMs": 1000,
+  "examples": {
+    "CLS": {
+      "script": "CLS",
+      "status": "ok",
+      "metric": "CLS",
+      "value": 0.0324,
+      "unit": "score",
+      "rating": "good",
+      "thresholds": {
+        "good": 0.1,
+        "needsImprovement": 0.25
+      },
+      "message": "CLS tracking active. Call getCLS() for updated value after page interactions.",
+      "getDataFn": "getCLS"
+    },
+    "INP": {
+      "script": "INP",
+      "status": "ok",
+      "metric": "INP",
+      "value": 64,
+      "unit": "ms",
+      "rating": "good",
+      "thresholds": {
+        "good": 200,
+        "needsImprovement": 500
+      },
+      "details": {
+        "totalInteractions": 1,
+        "worstEvent": "click → button#go",
+        "phases": {
+          "inputDelay": 1,
+          "processingTime": 61,
+          "presentationDelay": 3
+        }
+      }
+    },
+    "LCP": {
+      "script": "LCP",
+      "status": "ok",
+      "metric": "LCP",
+      "value": 68,
+      "unit": "ms",
+      "rating": "good",
+      "thresholds": {
+        "good": 2500,
+        "needsImprovement": 4000
+      },
+      "details": {
+        "element": "#hero",
+        "elementType": "Image",
+        "url": "http://127.0.0.1:56834/hero.png",
+        "sizePixels": 10000
+      }
+    },
+    "LCP-Image-Entropy": {
+      "script": "LCP-Image-Entropy",
+      "status": "ok",
+      "count": 3,
+      "details": {
+        "totalImages": 3,
+        "lowEntropyCount": 0,
+        "lcpElement": "img",
+        "lcpImageEligible": true,
+        "lcpImage": {
+          "url": "hero.png",
+          "bpp": 24.1384,
+          "isLowEntropy": false
+        }
+      },
+      "items": [
+        {
+          "url": "hero.png",
+          "width": 100,
+          "height": 100,
+          "displayedWidth": 600,
+          "displayedHeight": 400,
+          "fileSizeBytes": 30173,
+          "bpp": 24.1384,
+          "isLowEntropy": false,
+          "lcpEligible": true,
+          "isLCP": true
+        },
+        {
+          "url": "hero.png",
+          "width": 100,
+          "height": 100,
+          "displayedWidth": 300,
+          "displayedHeight": 200,
+          "fileSizeBytes": 30173,
+          "bpp": 24.1384,
+          "isLowEntropy": false,
+          "lcpEligible": true,
+          "isLCP": false
+        },
+        {
+          "url": "hero.png",
+          "width": 100,
+          "height": 100,
+          "displayedWidth": 300,
+          "displayedHeight": 200,
+          "fileSizeBytes": 30173,
+          "bpp": 24.1384,
+          "isLowEntropy": false,
+          "lcpEligible": true,
+          "isLCP": false
+        }
+      ],
+      "issues": []
+    },
+    "LCP-Subparts": {
+      "script": "LCP-Subparts",
+      "status": "ok",
+      "metric": "LCP",
+      "value": 64,
+      "unit": "ms",
+      "rating": "good",
+      "thresholds": {
+        "good": 2500,
+        "needsImprovement": 4000
+      },
+      "details": {
+        "element": "#hero",
+        "url": "hero.png",
+        "subParts": {
+          "ttfb": {
+            "value": 9,
+            "percent": 14,
+            "overTarget": false
+          },
+          "resourceLoadDelay": {
+            "value": 13,
+            "percent": 20,
+            "overTarget": true
+          },
+          "resourceLoadTime": {
+            "value": 8,
+            "percent": 13,
+            "overTarget": false
+          },
+          "elementRenderDelay": {
+            "value": 34,
+            "percent": 53,
+            "overTarget": true
+          }
+        },
+        "slowestPhase": "elementRenderDelay"
+      }
+    },
+    "LCP-Trail": {
+      "script": "LCP-Trail",
+      "status": "ok",
+      "metric": "LCP",
+      "value": 64,
+      "unit": "ms",
+      "rating": "good",
+      "thresholds": {
+        "good": 2500,
+        "needsImprovement": 4000
+      },
+      "details": {
+        "candidateCount": 1,
+        "finalElement": "#hero",
+        "candidates": [
+          {
+            "index": 1,
+            "selector": "#hero",
+            "time": 64,
+            "elementType": "Image",
+            "url": "hero.png"
+          }
+        ]
+      }
+    },
+    "LCP-Video-Candidate": {
+      "script": "LCP-Video-Candidate",
+      "status": "ok",
+      "metric": "LCP",
+      "value": 60,
+      "unit": "ms",
+      "rating": "good",
+      "thresholds": {
+        "good": 2500,
+        "needsImprovement": 4000
+      },
+      "details": {
+        "isVideo": true,
+        "lcpSource": "poster",
+        "posterUrl": "http://127.0.0.1:56834/hero.png",
+        "videoUrl": null,
+        "posterFormat": "png",
+        "posterPreloaded": false,
+        "fetchpriorityOnPreload": null,
+        "isCrossOrigin": false,
+        "videoAttributes": {
+          "autoplay": false,
+          "muted": false,
+          "playsinline": false,
+          "preload": "none"
+        }
+      },
+      "issues": [
+        {
+          "severity": "warning",
+          "message": "No <link rel=\"preload\" as=\"image\"> for the poster: the browser discovers it late"
+        },
+        {
+          "severity": "info",
+          "message": "Poster uses png; AVIF or WebP would reduce file size and LCP load time"
+        },
+        {
+          "severity": "warning",
+          "message": "preload=\"none\" on a non-autoplay video may delay poster image loading in some browsers"
+        }
+      ]
+    }
+  }
+}