Lot S, phase 2 : le quorum dans le serveur (ADR 0013), vu rouge puis vert

- migration 0011 (additive ; 0010 reste au lot V) : documents.quorums (par cran,
  NULL = vote_floor à chaque cran, le C d'avant), units.quorum (NULL = celui du
  cran), journaux quorum_changes et quorum_amendments ;
- quorum effectif = units.quorum ?? quorums[cran] ; les propositions d'inertie et
  les modules en héritent ; p0 = 2 × vote_floor / W, jamais le quorum d'un article ;
- route PUT /units/{id}/quorum { "quorum": n | null } : trustin_access::sets_quorum
  (l'auteur de la première version, un administrateur pour le seed), refusée dès
  qu'un vote existe (quorum::voted_units : vote du serveur, bulletin de la chaîne
  en attente ou confirmé, adoption) ; bornes 2..W, 1..W dans le groupe d'essai ;
- amendement gardé 2026-11-03-quorums-par-cran : écrit les quorums du seed là où
  il n'y en a pas, une fois par document, consigné, file de publication là où il
  publie ;
- JSON : evaluation.quorum / yesNeeded / noNeeded ; l'unité : quorum,
  quorumDefault, canSetQuorum ; doc.quorums ; levels[].quorum ; document.json
  publié : quorums ; adoptions.params : quorum (plus de constant) ;
- seed : quorums 12 · 12 · 50 · 50 · 50 (Monnaie libre), 1 partout (essai).
- tests : tests/quorum.rs (5) et les règles pures ; les scénarios du groupe
  d'essai qui demandaient deux voix posent le quorum 2 de l'article, comme son
  auteur le ferait ; les chiffres de Monnaie libre suivent (9 au cran 2, 39 au
  cran 3, 43 au cran 4).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/trustin-access/src/lib.rs

@@ -23,7 +23,10 @@
 //!   administrator; it is reiterated by the person who raised it only —
 //!   `lifts_objection` / `reiterates_objection`;
 //! - each person reads their own messages only — `reads_message`
-//!   (2026-10-31, lot F, ADR 0010).
+//!   (2026-10-31, lot F, ADR 0010);
+//! - the quorum of an article is set by the author of its first version — for a
+//!   text of the seed, by an administrator — and only before the first vote —
+//!   `sets_quorum` (2026-11-03, ADR 0013).
 
 use serde::{Deserialize, Serialize};
 
@@ -184,6 +187,24 @@ pub fn reads_message(identity: &Identity, recipient: &str) -> bool {
     identity.id == recipient
 }
 
+/// Who sets the quorum of an article (Yvv, 2026-11-02: « L'auteur, avant le 1er vote »,
+/// ADR 0013): the author of its first version; for an article without author (a text of
+/// the seed), an administrator of trustinWallet — never one for an author. Once a vote
+/// exists on the article (`voted`, the server's `quorum::a_vote_exists`), nobody: the
+/// votes cast were judged on it.
+pub fn sets_quorum(identity: &Identity, first_author: Option<&str>, voted: bool) -> bool {
+    if voted {
+        return false;
+    }
+    match first_author {
+        Some(author) => identity.id == author,
+        None => identity.admin,
+    }
+}
+
+/// The test group: hidden, the quorum 1 at every level — the one place one voice passes.
+pub const TEST_GROUP: &str = "essai";
+
 /// The groups a fresh deployment starts with. Ordered as displayed.
 pub fn default_groups() -> Vec<Group> {
     let g = |slug: &str, name: &str, parent: Option<&str>, policy, hidden| Group {
@@ -204,7 +225,7 @@ pub fn default_groups() -> Vec<Group> {
             GroupPolicy::Managed,
             false,
         ),
-        g("essai", "Groupe d'essai", None, GroupPolicy::Managed, true),
+        g(TEST_GROUP, "Groupe d'essai", None, GroupPolicy::Managed, true),
     ]
 }
 
@@ -308,6 +329,20 @@ mod tests {
         assert!(!lifts_objection(&other, "luna") && !reiterates_objection(&other, "luna"));
     }
 
+    #[test]
+    fn the_author_sets_the_quorum_before_the_first_vote_an_administrator_for_the_seed() {
+        let chiara = Identity { id: "chiara".into(), ..who(IdentityKind::Invite, false, false) };
+        let admin = Identity { id: "yvv".into(), ..who(IdentityKind::G1, true, true) };
+        let other = Identity { id: "luna".into(), ..who(IdentityKind::G1, true, false) };
+        assert!(sets_quorum(&chiara, Some("chiara"), false));
+        assert!(!sets_quorum(&chiara, Some("chiara"), true), "after the first vote, nobody");
+        assert!(!sets_quorum(&other, Some("chiara"), false));
+        assert!(!sets_quorum(&admin, Some("chiara"), false), "an administrator never sets it for an author");
+        assert!(sets_quorum(&admin, None, false), "a text of the seed: an administrator");
+        assert!(!sets_quorum(&admin, None, true));
+        assert!(!sets_quorum(&other, None, false));
+    }
+
     #[test]
     fn a_message_is_read_by_its_recipient_only() {
         let admin = Identity { id: "yvv".into(), ..who(IdentityKind::G1, true, true) };