feat(adapter): plain-css second-adapter smoke — proves the IR seam (WHYNOT-WP-0002 T10)

A deliberately-unfinished second adapter that consumes the same ir/ and honours
the same adapters/ADAPTER_CONTRACT.md (token full-gen + write-once stubs + drift
roll-up shape + exit codes), with zero changes to ir/. Every IR component is
'new' for a fresh stack → 10 class stubs + tokens.css (80 props). Not a usable
plain-CSS kit — the deliverable is confidence the boundary holds so the
architecture can be lifted into a coulomb-level tool later. make adapt-plain-css.

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

adapters/plain-css/_report.json

@@ -0,0 +1,106 @@
+{
+  "stack": "plain-css",
+  "generatedAt": "2026-06-30T07:20:50.544Z",
+  "components": [
+    {
+      "name": "Button",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-button class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "Eyebrow",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-eyebrow class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "Icon",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-icon class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "PageHeader",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-page-header class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "PipelineStrip",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-pipeline-strip class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "Sidebar",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-sidebar class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "StageDot",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-stage-dot class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "Stamp",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-stamp class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "Tag",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-tag class — stub generated."
+        }
+      ]
+    },
+    {
+      "name": "TopNav",
+      "status": "new",
+      "issues": [
+        {
+          "kind": "no-counterpart",
+          "detail": "no .wn-top-nav class — stub generated."
+        }
+      ]
+    }
+  ]
+}