chore(release): prep v0.1.16 — say plainly which servers Tane talks to

The store listing claimed "No account, no server, no trackers" while the
app was dialling four relays at launch. The app side is fixed; this is
the half a reader sees.

- Store description, both locales: the false line is gone, and a new
  "Sharing needs the internet" block names relay.comunes.org (ours),
  nos.lol, relay.damus.io and relay.primal.net, says when Tane talks to
  them, what they can see (a key and an IP — no name, no account), and
  where to switch any or all of them off, or point Tane at your own.
  Deliberately plain: no protocol names, no jargon. The audience is
  gardeners; the technical detail belongs in the F-Droid thread.
- The same correction on the landing page (feature card, FAQ, status).
- 0.1.16+18, so the F-Droid recipe's versionCodes become 181/182/183.
  F-Droid reads fastlane metadata from the checkout of the newest built
  version, so the description only reaches it via a new release.

The recipe mirror's `commit:` still points at v0.1.15 — it needs a hash
that does not exist yet, and is synced here and in the fdroiddata fork
once v0.1.16 is tagged.

apps/app_seeds/fastlane/metadata/android/en-US/changelogs/18.txt

@@ -0,0 +1 @@
+Tane now stays completely offline until you join the sharing part — it no longer contacts any server on its own. The store description finally says which community servers it talks to, what they can see, and how to change them or switch them all off.

apps/app_seeds/fastlane/metadata/android/en-US/full_description.txt

@@ -13,8 +13,11 @@ MANAGE YOUR BANK
 • Search and filter; snap a photo now and name it later.
 
 YOURS, AND ONLY YOURS
-• Works fully offline. No account, no server, no trackers.
+• Your seed book works with no internet at all. What you write stays on your
+  phone; nothing goes out unless you put some of your seeds up for sharing, or
+  write to someone.
 • Everything is encrypted at rest on your device.
+• No account, no sign-up, no ads, no trackers.
 • Save an encrypted backup and keep a printed recovery sheet — restore your
   whole bank on a new device.
 
@@ -22,6 +25,26 @@ SHARE, THE WAY IT'S ALWAYS BEEN DONE
 • Mark what you have spare to give away, swap or sell.
 • Print a catalog of what you share to take to a seed fair.
 
+SHARING NEEDS THE INTERNET
+Keeping your seed book needs nothing but your phone. Sharing does need a
+connection: to get an offer or a message across to someone, Tane leaves it on
+community servers — machines run by people, not by a company. Tane comes with
+four: relay.comunes.org, which Asociación Comunes runs (the same people who make
+Tane), plus three public ones that others already use — nos.lol, relay.damus.io
+and relay.primal.net.
+
+Tane only talks to them once you join the sharing part and agree to the
+community rules. Before that it doesn't connect to anything, and messaging stays
+switched off. Once you join, those servers see the key that stands for you and
+the address your phone connects from — no name, no email, no account. Your seed
+book itself is never sent anywhere.
+
+You stay in charge of that list of servers. In the sharing setup you can switch
+off any server on it, switch off every one of them — Tane then goes back to
+being a seed book that never connects — or add the address of a different
+server. Anyone can run a server of their own, and Tane works just as well with
+it.
+
 Tane is free software (AGPL-3.0). No ads, no commissions, no business model
 — it exists to support traditional varieties and push back against the seed
 monopoly.