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/content/_index.en.md

@@ -0,0 +1,34 @@
+---
+title: "Your seed bank in your pocket"
+description: "A local-first, decentralized app for keeping and sharing traditional seeds. Offline, encrypted, no account."
+hero:
+  title: "Your seed bank in your pocket"
+  tagline: "Keep and share traditional seeds — offline, encrypted, no account."
+  lead: >
+    Every traditional seed is a letter written by thousands of generations,
+    passed from hand to hand. Tane helps people and seed-saver collectives keep
+    a friendly inventory of their bank, decide what they offer, and share it
+    locally — without a central intermediary that could control it, censor it,
+    or be fined for it.
+pillars:
+  - icon: "🌱"
+    title: "Manage your bank"
+    body: "Add a seed with just a photo and a name — no Latin required. Note the year, how much you have, where it came from, germination tests. Search, filter, snap now and name later."
+  - icon: "🔒"
+    title: "Yours, and only yours"
+    body: "Works fully offline. No account, no server, no trackers. Everything is encrypted on your device. Keep an encrypted backup and a printed recovery sheet to restore your whole bank on a new device."
+  - icon: "🤝"
+    title: "Share, as it's always been done"
+    body: "Mark what you have spare to give away, swap or sell. Someone nearby finds it and contacts you — no middleman. Print a catalog of what you share to take to a seed fair."
+values:
+  title: "Why Tane is different"
+  points:
+    - "No center: no company can shut it down, censor it, or be fined for it."
+    - "Anti-monopoly by design — sharing seeds multiplies the commons instead of depleting it."
+    - "Spreads like a seed, person to person, with no server in the middle."
+    - "Free software (AGPL-3.0). No ads, no commissions, no business model."
+---
+
+Tane (種, "seed"; from *tanemaki* 種まき, "to sow seeds") is a local-first,
+decentralized app for keeping and sharing traditional seeds. It works with zero
+network — and connects you to a neighborly seed-sharing network when you want it.