feat(core,cli): harden install engine and extend skill lint and interview eval

- update only touches the recorded project root; project installs do not
  follow symlinks or junctions; repeated --force rotates .orig backups;
  uninstall never deletes outside the recorded root
- run npm/npx without a shell on Windows and pin optional tool versions
- skip the update check in CI and non-interactive output
- lint: cross-document section pointers, preflight row ids, gate rule
  numbers, per-document size budgets, gate copy equality
- eval: scenarios S19-S21, route and read-cost rejudging, interpretation
  card judging, temp-dir previews and table-form cards no longer fail

build/eval/interview/fixtures/s20-derived-state-token/index.html

@@ -0,0 +1,36 @@
+<!doctype html>
+<html lang="ko">
+<head>
+  <meta charset="utf-8" />
+  <title>책잇다 — 독서 모임</title>
+  <style>
+    :root {
+      --color-bg: #f4f1ea;
+      --color-ink: #1c2330;
+      --color-accent: #23408e;
+      --font-family: "Pretendard", system-ui, sans-serif;
+      --radius-base: 4px;
+    }
+    body { margin: 0; background: var(--color-bg); color: var(--color-ink); font-family: var(--font-family); }
+    .hero { padding: 96px 24px; }
+    .hero h1 { font-size: 2.5rem; margin: 0 0 16px; }
+    .cta {
+      display: inline-block;
+      margin-top: 24px;
+      padding: 14px 28px;
+      background: var(--color-accent);
+      color: #fff;
+      border-radius: var(--radius-base);
+      text-decoration: none;
+      font-weight: 600;
+    }
+    .cta:hover { opacity: 0.97; }
+  </style>
+</head>
+<body>
+  <section class="hero">
+    <h1>이번 달 함께 읽을 책</h1>
+    <a class="cta" href="#apply">모임 신청하기</a>
+  </section>
+</body>
+</html>