docs: the Markdown is the policy, the site renders it

Reverses yesterday's framing. The policy is reviewed here like any other
change; the Astro page holds no prose of its own — the website build
checks this repository out beside itself and renders this file through a
content collection, so there is one copy of the text anywhere and drift is
impossible rather than merely detectable.

Both app repos are public on Codeberg, so the site needs no token to read
them and nothing has to run on the Codeberg side.

docs/PRIVACY.md

@@ -1,16 +1,15 @@
 # Agendula — privacy policy
 
-> **The published policy does not live in this repository.** It is
-> <https://jeanlucmakiola.de/agendula/privacy>, built from
-> `src/pages/agendula/privacy.astro` in the website repo
-> ([source](https://gitea.jeanlucmakiola.de/makiolaj/jeanlucmakiola.de/src/branch/main/src/pages/agendula/privacy.astro) —
-> self-hosted Gitea, same shape as Calendula's page). That URL is what the app's
-> **Settings → Privacy policy** row opens and what the Play Console field must
-> hold.
+> **This file is the policy.** Edit it here, in a PR, reviewed like any other
+> change — it is the source of truth.
 >
-> This file is the text of record until that page ships, and then becomes a
-> pointer to it. Edit the Astro page, not this — or they will disagree, and the
-> one users read is the other one.
+> It is *published* at <https://jeanlucmakiola.de/agendula/privacy>, which is
+> what the app's **Settings → Privacy policy** row opens and what the Play
+> Console field must hold. That page holds no copy of the prose: the website
+> build checks this repository out beside itself and renders this file through
+> an Astro content collection, so there is exactly one copy of the policy
+> anywhere and the two cannot drift. An edit here reaches the live page on the
+> site's next build.
 
 _Last updated: 2026-09-07._