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.

apps/app_seeds/test/screenshots/README.md

@@ -0,0 +1,43 @@
+# Localized app screenshots
+
+Golden-based harness that renders key screens as PNGs in several languages, for
+the landing site (`tane.comunes.org`) and the app-store listings. No emulator —
+it runs under `flutter test`, so it's deterministic and CI-friendly.
+
+## Regenerate
+
+```sh
+cd apps/app_seeds
+flutter test --update-goldens --run-skipped --tags screenshots test/screenshots/screenshots_test.dart
+tool/collect_screenshots.sh   # copy PNGs into site/ and fastlane/
+```
+
+Drop `--update-goldens` to *verify* the committed PNGs still match. The
+`screenshots` tag is **skipped by default** (`dart_test.yaml`) — so it never
+runs in the normal suite or CI's `flutter test --coverage`, where golden pixel
+differences across OS/font versions would cause false failures. `--run-skipped`
+opts it back in.
+
+## What it produces
+
+`goldens/<locale>/<screen>.png` for **en, es, fr, de, pt, ja**, screens
+**home · inventory · market · calendar · detail**, plus `goldens/rtl/inventory.png`.
+The market is rendered populated via a seeded `OffersCubit` with a no-op transport
+(no network); home/calendar/detail/inventory render from the repository alone.
+
+- Fonts: real glyphs come from `loadScreenshotFonts()` — every family in
+  `FontManifest.json` (MaterialIcons + bundled Noto/seedks) plus the bundled
+  **DejaVu Sans** as the Latin text face. No Roboto needed.
+- `rtl/` is a **layout demo**, not a locale: English strings forced
+  right-to-left to prove the design is RTL-safe. The app ships no Arabic
+  translation yet, so there is deliberately no `ar/` with Arabic copy.
+- Partial locales (e.g. `ja`) fall back to English for untranslated strings —
+  that's the app's real runtime behavior, shown honestly.
+- These are raw device-canvas frames (no marketing captions or device bezels).
+  Add those downstream only if a store rejects plain screenshots.
+
+## Adding a screen or locale
+
+Edit `screenshotLocales` / the `screens` map in `screenshots_test.dart`. Screens
+must render from the repository + cubits alone (no live Nostr/network stack), so
+inventory/detail/calendar are the safe, self-contained set.