feat(web): tane.comunes.org landing + localized app screenshots

- Hugo site (site/): EN/ES intro + legal (generated from docs/legal), an
  ES/EN About page from docs/{que-es-tane,what-is-tane}.md, seed-green theme,
  responsive header, store-badge placeholders, multi-stage Hugo->nginx image.
- Golden screenshot harness (test/screenshots/): en,es,fr,de,pt,ja + RTL demo,
  real fonts via DejaVu Sans + FontManifest; skip-by-default tag so CI stays
  green. collect_screenshots.sh feeds site/ and fastlane phoneScreenshots.
- Drop editorial notes from the public explainer.

site/layouts/index.html

@@ -0,0 +1,53 @@
+{{ define "main" }}
+{{ $lang := .Site.Language.Lang }}
+<section class="hero">
+  <div class="hero-copy">
+    <h1>{{ .Params.hero.title }}</h1>
+    <p class="tagline">{{ .Params.hero.tagline }}</p>
+    <p class="lead">{{ .Params.hero.lead }}</p>
+    {{ .Content }}
+    {{ partial "store-badges.html" . }}
+  </div>
+  {{ $shot := resources.Get (printf "screenshots/%s/inventory.png" $lang) }}
+  {{ with $shot }}
+  <div class="hero-shot">
+    <div class="phone"><img src="{{ .RelPermalink }}" alt="Tane inventory" loading="eager" /></div>
+  </div>
+  {{ end }}
+</section>
+
+<section class="pillars">
+  {{ range .Params.pillars }}
+  <article class="pillar">
+    <div class="pillar-icon" aria-hidden="true">{{ .icon }}</div>
+    <h2>{{ .title }}</h2>
+    <p>{{ .body }}</p>
+  </article>
+  {{ end }}
+</section>
+
+{{ $screens := slice "home" "inventory" "market" "calendar" "detail" }}
+<section class="shots">
+  <h2>{{ T "screenshotsTitle" }}</h2>
+  <div class="shot-row">
+    {{ range $s := $screens }}
+      {{ $img := resources.Get (printf "screenshots/%s/%s.png" $lang $s) }}
+      {{ with $img }}
+      <div class="phone"><img src="{{ .RelPermalink }}" alt="Tane {{ $s }}" loading="lazy" /></div>
+      {{ end }}
+    {{ end }}
+  </div>
+</section>
+
+<section class="values">
+  <h2>{{ .Params.values.title }}</h2>
+  <ul>
+    {{ range .Params.values.points }}<li>{{ . }}</li>{{ end }}
+  </ul>
+</section>
+
+<section class="get-it" id="get">
+  <h2>{{ T "getItTitle" }}</h2>
+  {{ partial "store-badges.html" . }}
+</section>
+{{ end }}