feat(adapter): Lit component scaffold + drift report (WHYNOT-WP-0002 T07)

Extend make adapt-lit beyond tokens: parse src/elements/*.js, compare each IR
component contract against its <wn-*> element, and emit per-component drift
reports + a machine roll-up (adapters/lit/drift/), with write-once stubs
(adapters/lit/stubs/) for genuinely new components. Never overwrites
hand-authored sources.

- Severity split: actionable drift (prop-missing, attribute-mismatch,
  variant-axis-missing, tag-mismatch) gates with exit 3; non-portable + prop-extra
  are informational (the IR carries React style/onClick; Lit is richer than the
  minimal designbook) and don't gate.
- Current state: 7 ok, 3 actionable drift for human triage — PipelineStrip
  (wn-pipeline-strip vs hand-authored wn-pipeline rename), PageHeader (actions is
  a slot, not a prop), Sidebar (IR 'current' axis absent on the element).
- _report.json reuses generatedAt/irRef when drift is unchanged (no git churn).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

adapters/lit/adapt.mjs

@@ -16,13 +16,18 @@
 // type/utility CSS after it is preserved untouched. Re-running with an unchanged
 // ir/tokens.json is a no-op (byte-identical output).
 // =============================================================
-import { readFileSync, writeFileSync, existsSync } from "node:fs";
+import { readFileSync, writeFileSync, existsSync, mkdirSync, readdirSync, rmSync } from "node:fs";
+import { execSync } from "node:child_process";
 import { join, dirname } from "node:path";
 import { fileURLToPath } from "node:url";
+import { parseLitElements, componentDrift, renderStub } from "./scaffold.mjs";
 
 const REPO = join(dirname(fileURLToPath(import.meta.url)), "..", "..");
 const TOKENS_JSON = join(REPO, "ir", "tokens.json");
 const TOKEN_CSS = join(REPO, "src", "styles", "colors_and_type.css");
+const IR_COMPONENTS = join(REPO, "ir", "components");
+const DRIFT_DIR = join(REPO, "adapters", "lit", "drift");
+const STUBS_DIR = join(REPO, "adapters", "lit", "stubs");
 
 const BEGIN = "/* @generated tokens — regenerated by `make adapt-lit` from ir/tokens.json. DO NOT EDIT. */";
 const END = "/* @end generated tokens */";
@@ -85,10 +90,104 @@ function generateTokens() {
   console.log(`tokens: regenerated ${count} custom properties → src/styles/colors_and_type.css`);
 }
 
+// ---------- T07: component scaffold + drift ----------
+function irRef() {
+  try {
+    return execSync("git rev-parse --short HEAD", { cwd: REPO }).toString().trim();
+  } catch { return "(no-git)"; }
+}
+
+function renderDriftMd(c) {
+  const head = {
+    ok: "✓ in sync with the IR contract.",
+    drift: "⚠ drift detected — resolve per `.claude/rules/designbook-propagation.md`.",
+    new: "＋ new component — a stub was generated; integrate it.",
+    removed: "－ removed from the IR.",
+  }[c.status];
+  const lines = [
+    `<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->`,
+    `# Drift — ${c.name} \`<${c.tag}>\``,
+    "",
+    `**Status:** ${c.status} — ${head}`,
+    "",
+  ];
+  if (!c.issues.length) lines.push("No issues.");
+  else {
+    lines.push("| severity | kind | prop | detail |", "| --- | --- | --- | --- |");
+    const order = { drift: 0, info: 1 };
+    for (const i of [...c.issues].sort((a, b) => order[a.severity] - order[b.severity])) {
+      const detail = i.detail || (i.expected !== undefined ? `expected \`${i.expected}\`, actual \`${i.actual}\`` : "");
+      lines.push(`| ${i.severity === "drift" ? "**drift**" : "info"} | ${i.kind} | ${i.prop ? `\`${i.prop}\`` : "—"} | ${detail} |`);
+    }
+  }
+  lines.push("");
+  return lines.join("\n");
+}
+
+function runScaffold() {
+  if (!existsSync(IR_COMPONENTS)) {
+    console.error("No ir/components/ — run `make ir` first.");
+    process.exit(2);
+  }
+  const byTag = parseLitElements(REPO);
+  const contracts = readdirSync(IR_COMPONENTS).filter((f) => f.endsWith(".json"))
+    .map((f) => JSON.parse(readFileSync(join(IR_COMPONENTS, f), "utf8")));
+
+  const results = contracts.map((c) => componentDrift(c, byTag))
+    .sort((a, b) => a.name.localeCompare(b.name));
+
+  // Per-component drift docs: snapshot, so wipe stale ones first (idempotency rule 4).
+  mkdirSync(DRIFT_DIR, { recursive: true });
+  for (const f of readdirSync(DRIFT_DIR)) if (f.endsWith(".md")) rmSync(join(DRIFT_DIR, f));
+  for (const c of results) writeFileSync(join(DRIFT_DIR, `${c.name}.md`), renderDriftMd(c));
+
+  // Machine roll-up. Reuse generatedAt when nothing material changed so a no-op
+  // `make adapt-lit` produces no git churn (matches ir/manifest.json discipline).
+  const reportPath = join(DRIFT_DIR, "_report.json");
+  let generatedAt = new Date().toISOString();
+  let ref = irRef();
+  if (existsSync(reportPath)) {
+    try {
+      const prev = JSON.parse(readFileSync(reportPath, "utf8"));
+      if (JSON.stringify(prev.components) === JSON.stringify(results)) {
+        if (prev.generatedAt) generatedAt = prev.generatedAt;
+        if (prev.irRef) ref = prev.irRef; // unchanged drift ⇒ keep the prior ref, no churn
+      }
+    } catch { /* regenerate fresh */ }
+  }
+  const report = { stack: "lit", generatedAt, irRef: ref, components: results };
+  writeFileSync(reportPath, JSON.stringify(report, null, 2) + "\n");
+
+  // Write-once stubs for genuinely new components.
+  let stubbed = 0;
+  for (const c of results.filter((r) => r.status === "new")) {
+    mkdirSync(STUBS_DIR, { recursive: true });
+    const out = join(STUBS_DIR, `${c.name}.js`);
+    if (!existsSync(out)) { writeFileSync(out, renderStub(contracts.find((x) => x.name === c.name))); stubbed++; }
+  }
+
+  const drift = results.filter((r) => r.status === "drift");
+  const isNew = results.filter((r) => r.status === "new");
+  const ok = results.filter((r) => r.status === "ok");
+  const infoCount = ok.reduce((n, r) => n + r.issues.length, 0);
+  console.log(`scaffold: ${ok.length} ok · ${drift.length} drift · ${isNew.length} new (${stubbed} stub${stubbed === 1 ? "" : "s"} written) → adapters/lit/drift/`);
+  if (infoCount) console.log(`  (${infoCount} informational note${infoCount === 1 ? "" : "s"} on in-sync components — non-portable/extra props, not gated)`);
+  for (const c of [...drift, ...isNew]) {
+    const actionable = c.issues.filter((i) => i.severity === "drift");
+    console.log(`  ${c.status === "drift" ? "⚠" : "＋"} ${c.name}: ${actionable.map((i) => `${i.kind}(${i.prop ?? ""})`).join(", ") || c.issues.map((i) => i.kind).join(", ")}`);
+  }
+
+  return drift.length + isNew.length > 0; // → drift exit code
+}
+
 function main() {
   generateTokens();
-  // T07 will add: component stub scaffolding + drift reports here.
-  console.log("adapt-lit: tokens done. (component scaffold + drift: T07)");
+  const drifted = runScaffold();
+  if (drifted) {
+    console.log("adapt-lit: drift detected — see adapters/lit/drift/. Exit 3 (review, non-fatal).");
+    process.exit(3);
+  }
+  console.log("adapt-lit: tokens + scaffold done, no drift.");
 }
 
 main();

adapters/lit/drift/Button.md

@@ -0,0 +1,14 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Button `<wn-button>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `onClick` | type=function; not attribute-mappable — handle explicitly, never drop. |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |
+| info | prop-extra | `size` | on <wn-button> (attribute 'size'), not in IR contract. |
+| info | prop-extra | `iconEnd` | on <wn-button> (attribute 'icon-end'), not in IR contract. |
+| info | prop-extra | `type` | on <wn-button> (attribute 'type'), not in IR contract. |
+| info | prop-extra | `disabled` | on <wn-button> (attribute 'disabled'), not in IR contract. |
+| info | prop-extra | `href` | on <wn-button> (attribute 'href'), not in IR contract. |

adapters/lit/drift/Eyebrow.md

@@ -0,0 +1,9 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Eyebrow `<wn-eyebrow>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |
+| info | prop-extra | `strong` | on <wn-eyebrow> (attribute 'strong'), not in IR contract. |

adapters/lit/drift/Icon.md

@@ -0,0 +1,8 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Icon `<wn-icon>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |

adapters/lit/drift/PageHeader.md

@@ -0,0 +1,9 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — PageHeader `<wn-page-header>`
+
+**Status:** drift — ⚠ drift detected — resolve per `.claude/rules/designbook-propagation.md`.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| **drift** | prop-missing | `actions` | in IR (attribute 'actions'), absent on <wn-page-header> |
+| info | prop-extra | `hasActions` | on <wn-page-header> (attribute 'hasactions'), not in IR contract. |

adapters/lit/drift/PipelineStrip.md

@@ -0,0 +1,8 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — PipelineStrip `<wn-pipeline-strip>`
+
+**Status:** drift — ⚠ drift detected — resolve per `.claude/rules/designbook-propagation.md`.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| **drift** | tag-mismatch | — | IR contract tag 'wn-pipeline-strip' has no element; 'wn-pipeline' looks like the hand-authored counterpart (rename — resolve in Claude Design or realign the element). |

adapters/lit/drift/Sidebar.md

@@ -0,0 +1,11 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Sidebar `<wn-sidebar>`
+
+**Status:** drift — ⚠ drift detected — resolve per `.claude/rules/designbook-propagation.md`.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| **drift** | prop-missing | `current` | in IR (attribute 'current'), absent on <wn-sidebar> |
+| **drift** | variant-axis-missing | `current` | IR variant axis 'current' (doc:) has no Lit property. |
+| info | non-portable | `onNav` | type=function; not attribute-mappable — handle explicitly, never drop. |
+| info | prop-extra | `activation` | on <wn-sidebar> (attribute 'activation'), not in IR contract. |

adapters/lit/drift/StageDot.md

@@ -0,0 +1,8 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — StageDot `<wn-stage-dot>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |

adapters/lit/drift/Stamp.md

@@ -0,0 +1,8 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Stamp `<wn-stamp>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |

adapters/lit/drift/Tag.md

@@ -0,0 +1,8 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — Tag `<wn-tag>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `style` | type=object; not attribute-mappable — handle explicitly, never drop. |

adapters/lit/drift/TopNav.md

@@ -0,0 +1,11 @@
+<!-- @generated by make adapt-lit (WHYNOT-WP-0002 T07) — overwritten each run; do not hand-edit. -->
+# Drift — TopNav `<wn-top-nav>`
+
+**Status:** ok — ✓ in sync with the IR contract.
+
+| severity | kind | prop | detail |
+| --- | --- | --- | --- |
+| info | non-portable | `onNew` | type=function; not attribute-mappable — handle explicitly, never drop. |
+| info | prop-extra | `logoSrc` | on <wn-top-nav> (attribute 'logo-src'), not in IR contract. |
+| info | prop-extra | `brand` | on <wn-top-nav> (attribute 'brand'), not in IR contract. |
+| info | prop-extra | `slug` | on <wn-top-nav> (attribute 'slug'), not in IR contract. |

adapters/lit/drift/_report.json

@@ -0,0 +1,222 @@
+{
+  "stack": "lit",
+  "generatedAt": "2026-06-30T07:01:40.219Z",
+  "irRef": "17f2ad9",
+  "components": [
+    {
+      "name": "Button",
+      "status": "ok",
+      "tag": "wn-button",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "onClick",
+          "detail": "type=function; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        },
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "size",
+          "detail": "on <wn-button> (attribute 'size'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "iconEnd",
+          "detail": "on <wn-button> (attribute 'icon-end'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "type",
+          "detail": "on <wn-button> (attribute 'type'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "disabled",
+          "detail": "on <wn-button> (attribute 'disabled'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "href",
+          "detail": "on <wn-button> (attribute 'href'), not in IR contract.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "Eyebrow",
+      "status": "ok",
+      "tag": "wn-eyebrow",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "strong",
+          "detail": "on <wn-eyebrow> (attribute 'strong'), not in IR contract.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "Icon",
+      "status": "ok",
+      "tag": "wn-icon",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "PageHeader",
+      "status": "drift",
+      "tag": "wn-page-header",
+      "issues": [
+        {
+          "kind": "prop-missing",
+          "prop": "actions",
+          "detail": "in IR (attribute 'actions'), absent on <wn-page-header>",
+          "severity": "drift"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "hasActions",
+          "detail": "on <wn-page-header> (attribute 'hasactions'), not in IR contract.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "PipelineStrip",
+      "status": "drift",
+      "tag": "wn-pipeline-strip",
+      "issues": [
+        {
+          "kind": "tag-mismatch",
+          "expected": "wn-pipeline-strip",
+          "actual": "wn-pipeline",
+          "detail": "IR contract tag 'wn-pipeline-strip' has no element; 'wn-pipeline' looks like the hand-authored counterpart (rename — resolve in Claude Design or realign the element).",
+          "severity": "drift"
+        }
+      ]
+    },
+    {
+      "name": "Sidebar",
+      "status": "drift",
+      "tag": "wn-sidebar",
+      "issues": [
+        {
+          "kind": "prop-missing",
+          "prop": "current",
+          "detail": "in IR (attribute 'current'), absent on <wn-sidebar>",
+          "severity": "drift"
+        },
+        {
+          "kind": "non-portable",
+          "prop": "onNav",
+          "detail": "type=function; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        },
+        {
+          "kind": "variant-axis-missing",
+          "prop": "current",
+          "detail": "IR variant axis 'current' (doc:) has no Lit property.",
+          "severity": "drift"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "activation",
+          "detail": "on <wn-sidebar> (attribute 'activation'), not in IR contract.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "StageDot",
+      "status": "ok",
+      "tag": "wn-stage-dot",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "Stamp",
+      "status": "ok",
+      "tag": "wn-stamp",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "Tag",
+      "status": "ok",
+      "tag": "wn-tag",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "style",
+          "detail": "type=object; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        }
+      ]
+    },
+    {
+      "name": "TopNav",
+      "status": "ok",
+      "tag": "wn-top-nav",
+      "issues": [
+        {
+          "kind": "non-portable",
+          "prop": "onNew",
+          "detail": "type=function; not attribute-mappable — handle explicitly, never drop.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "logoSrc",
+          "detail": "on <wn-top-nav> (attribute 'logo-src'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "brand",
+          "detail": "on <wn-top-nav> (attribute 'brand'), not in IR contract.",
+          "severity": "info"
+        },
+        {
+          "kind": "prop-extra",
+          "prop": "slug",
+          "detail": "on <wn-top-nav> (attribute 'slug'), not in IR contract.",
+          "severity": "info"
+        }
+      ]
+    }
+  ]
+}

adapters/lit/scaffold.mjs

@@ -0,0 +1,196 @@
+// =============================================================
+// adapters/lit/scaffold.mjs — component scaffold + drift (WHYNOT-WP-0002 · T07)
+//
+// Pure functions over ir/ + the Lit source tree (src/elements/*.js). Per
+// adapters/ADAPTER_CONTRACT.md:
+//   • IR component with no <wn-*> counterpart → a write-once STUB
+//     (adapters/lit/stubs/<Name>.js), never into the hand-authored tree.
+//   • IR component with a counterpart → a DRIFT REPORT
+//     (adapters/lit/drift/<Name>.md + a machine roll-up); never an overwrite.
+//
+// Behaviour is never generated — stubs carry a TODO; drift is for human triage.
+// =============================================================
+import { readFileSync, readdirSync, existsSync } from "node:fs";
+import { join } from "node:path";
+
+const ELEMENT_FILES = ["atoms.js", "form.js", "layout.js", "chrome.js"];
+
+// ---------- Parse the Lit source tree → tag → element descriptor ----------
+// Extract the balanced { … } block that starts at/after `from`.
+function balancedBlock(src, from) {
+  let i = src.indexOf("{", from), depth = 0;
+  const begin = i;
+  for (; i < src.length; i++) {
+    if (src[i] === "{") depth++;
+    else if (src[i] === "}" && --depth === 0) return src.slice(begin, i + 1);
+  }
+  return src.slice(begin);
+}
+
+// Parse a `static properties = { … }` block body into { name: {attribute,type,reflect} }.
+function parseProps(block) {
+  const props = {};
+  // Each entry: `name: { … },` — scan key then its balanced object.
+  const re = /([A-Za-z_$][\w$]*)\s*:\s*\{/g;
+  let m;
+  while ((m = re.exec(block))) {
+    const name = m[1];
+    const decl = balancedBlock(block, m.index + m[0].length - 1);
+    const attrM = /attribute\s*:\s*(false|"([^"]+)"|'([^']+)')/.exec(decl);
+    const typeM = /type\s*:\s*([A-Za-z]+)/.exec(decl);
+    const reflect = /reflect\s*:\s*true/.test(decl);
+    let attribute;
+    if (attrM) attribute = attrM[1] === "false" ? false : (attrM[2] || attrM[3]);
+    else attribute = name.toLowerCase(); // Lit default: lowercased property name
+    props[name] = { attribute, type: typeM ? typeM[1] : "String", reflect };
+    re.lastIndex = m.index + m[0].length; // resume after the key (decl re-scanned harmlessly)
+  }
+  return props;
+}
+
+// Find a class's own `static properties` (walks `extends` within the same file set).
+function classProps(name, classes) {
+  const cls = classes[name];
+  if (!cls) return {};
+  const own = cls.propsBlock ? parseProps(cls.propsBlock) : {};
+  const inherited = cls.extends && classes[cls.extends] ? classProps(cls.extends, classes) : {};
+  return { ...inherited, ...own };
+}
+
+export function parseLitElements(repo) {
+  const classes = {}; // className → { propsBlock, extends, file }
+  const defines = []; // { tag, className, file }
+  for (const file of ELEMENT_FILES) {
+    const path = join(repo, "src", "elements", file);
+    if (!existsSync(path)) continue;
+    const src = readFileSync(path, "utf8");
+    const classRe = /class\s+([A-Za-z_$][\w$]*)\s+extends\s+([A-Za-z_$][\w$]*)/g;
+    let m;
+    while ((m = classRe.exec(src))) {
+      const [className, base] = [m[1], m[2]];
+      const propsAt = src.indexOf("static properties", m.index);
+      // bound the search to before the next class declaration
+      classRe.lastIndex = m.index + m[0].length;
+      const nextClass = src.indexOf("class ", m.index + m[0].length);
+      const propsBlock = propsAt !== -1 && (nextClass === -1 || propsAt < nextClass)
+        ? balancedBlock(src, propsAt) : null;
+      classes[className] = { propsBlock, extends: base, file };
+    }
+    const defRe = /customElements\.define\(\s*["']([\w-]+)["']\s*,\s*([A-Za-z_$][\w$]*)\s*\)/g;
+    while ((m = defRe.exec(src))) defines.push({ tag: m[1], className: m[2], file });
+  }
+  const byTag = {};
+  for (const d of defines) byTag[d.tag] = { ...d, props: classProps(d.className, classes) };
+  return byTag;
+}
+
+// ---------- Drift: IR contract vs Lit element ----------
+// Actionable drift gates `make adapt-lit` (exit 3). The rest is informational:
+//   • non-portable — React style/callbacks that inherently have no attribute form;
+//     the Lit element is correct to omit them. Surfaced (never dropped), never gated.
+//   • prop-extra   — the Lit element is richer than the minimal React designbook;
+//     a divergence worth noting, but not a defect to block on.
+const ACTIONABLE = new Set(["prop-missing", "attribute-mismatch", "variant-axis-missing", "tag-mismatch"]);
+
+export function litAttrOf(decl) {
+  return decl.attribute === false ? null : decl.attribute;
+}
+
+function classify(issues) {
+  for (const i of issues) i.severity = ACTIONABLE.has(i.kind) ? "drift" : "info";
+  return issues.some((i) => i.severity === "drift") ? "drift" : "ok";
+}
+
+// Find a likely renamed counterpart when no exact tag match (e.g. wn-pipeline-strip → wn-pipeline).
+function likelyCounterpart(tag, byTag) {
+  if (byTag[tag]) return null;
+  const head = tag.replace(/^wn-/, "").split("-")[0]; // "pipeline"
+  const hit = Object.keys(byTag).find((t) => t.replace(/^wn-/, "").split("-")[0] === head);
+  return hit || null;
+}
+
+export function componentDrift(contract, byTag) {
+  const tag = contract.tag;
+  const el = byTag[tag];
+
+  if (!el) {
+    const alt = likelyCounterpart(tag, byTag);
+    if (alt) {
+      const issues = [{ kind: "tag-mismatch", expected: tag, actual: alt,
+        detail: `IR contract tag '${tag}' has no element; '${alt}' looks like the hand-authored counterpart (rename — resolve in Claude Design or realign the element).` }];
+      return { name: contract.name, status: classify(issues), tag, issues };
+    }
+    return { name: contract.name, status: "new", tag, issues: [
+      { kind: "no-counterpart", detail: `no <${tag}> in src/elements/ — stub generated.` },
+    ] };
+  }
+
+  const issues = [];
+  const litProps = el.props;
+  for (const p of contract.props || []) {
+    if (p.portable === false) {
+      issues.push({ kind: "non-portable", prop: p.name,
+        detail: `type=${p.type}; not attribute-mappable — handle explicitly, never drop.` });
+      continue;
+    }
+    if (p.attribute === false) continue; // property-only by contract
+    const lit = litProps[p.name];
+    if (!lit) {
+      issues.push({ kind: "prop-missing", prop: p.name,
+        detail: `in IR (attribute '${p.attribute}'), absent on <${tag}>` });
+      continue;
+    }
+    const litAttr = litAttrOf(lit);
+    if (litAttr !== p.attribute) {
+      issues.push({ kind: "attribute-mismatch", prop: p.name, expected: p.attribute, actual: litAttr === null ? "(property-only)" : litAttr });
+    }
+  }
+  // Variant axes must have a backing property.
+  for (const v of contract.variants || []) {
+    if (!litProps[v.axis]) issues.push({ kind: "variant-axis-missing", prop: v.axis,
+      detail: `IR variant axis '${v.axis}' (${v.values.join("/")}) has no Lit property.` });
+  }
+  // Extra Lit properties not described by the IR contract.
+  const irNames = new Set((contract.props || []).map((p) => p.name));
+  for (const name of Object.keys(litProps)) {
+    if (!irNames.has(name)) issues.push({ kind: "prop-extra", prop: name,
+      detail: `on <${tag}> (attribute '${litAttrOf(litProps[name]) ?? "(property-only)"}'), not in IR contract.` });
+  }
+
+  return { name: contract.name, status: classify(issues), tag, issues };
+}
+
+// ---------- Stub generation (write-once) ----------
+export function renderStub(contract) {
+  const tag = contract.tag;
+  const cls = "Wn" + contract.name;
+  const props = (contract.props || []).filter((p) => p.portable !== false && p.attribute !== false);
+  const litType = (t) => (t === "boolean" ? "Boolean" : t === "number" ? "Number" : "String");
+  const propLines = props.map((p) => {
+    const attr = p.attribute !== p.name.toLowerCase() ? `, attribute: "${p.attribute}"` : "";
+    return `    ${p.name}: { type: ${litType(p.type)}${attr} },`;
+  }).join("\n");
+  const nonPortable = (contract.props || []).filter((p) => p.portable === false);
+  const npNote = nonPortable.length
+    ? `\n  // Non-portable props (handle explicitly, do not drop): ${nonPortable.map((p) => p.name).join(", ")}.`
+    : "";
+  const slotMarkup = (contract.slots || []).some((s) => s.name === "default")
+    ? "<slot></slot>" : "";
+  return `// @generated STUB by adapters/lit (WHYNOT-WP-0002 T07) — from ir/components/${contract.name}.json.
+// Write-once scaffold: skeleton + typed reactive properties + a behaviour TODO.
+// Move into src/elements/ and implement; the adapter never overwrites this once edited.
+import { LitElement, html } from "lit";
+
+export class ${cls} extends LitElement {
+  createRenderRoot() { return this; } // light DOM, matches the existing wn-* elements${npNote}
+  static properties = {
+${propLines || "    // (no attribute-mappable props in the contract)"}
+  };
+  render() {
+    // TODO(${contract.name}): implement per ir/exemplars/${contract.name}.html and the design language.
+    return html\`<div class="${tag}" part="root">${slotMarkup}</div>\`;
+  }
+}
+// customElements.define("${tag}", ${cls});  // ← uncomment when integrating
+`;
+}