feat(site): rework 19 marketing showcases for composition diversity

Measured convergence before: split hero 13/19, top-bar nav 19/19,
one-line notice footer 14/19, body Pretendard 17/21, 10 similarity
pairs above 0.78. Each showcase got a pre-assigned hero family, nav
form, footer form, type pair, background, accent hue, radius, motion
grammar and material from outputs/rework-2026-10-06/plan.md; direction
cards and the chosen reason are recorded in every design.md.

After: 0 similarity warnings, 19 distinct display faces, 7 hero
families, 5 nav forms, 5 footer forms, no scroll reveals, 5 showcases
with SVG filter materials. Example contact values replace bracket
placeholders under the existing fictional-brand notices. Thumbnails,
OG images, card copy and three e2e assertions updated; dead CSS in
dure-enrollment and hannam-jari removed; similarity.mjs learns the new
font families.

apps/site/package.json

@@ -19,6 +19,7 @@
     "postbuild": "node tools/no-hanja.mjs --root dist",
     "preview": "astro preview",
     "test:no-hanja": "node tools/no-hanja.mjs",
+    "test:similarity": "node tools/similarity.mjs",
     "typecheck": "echo \"(사이트는 build 로 검증한다)\"",
     "verify": "node tools/verify.mjs"
   },