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

Le quorum Q (votants = pour + contre) remplace le C additif : T' = max(T, Q),
la version passe si pour ≥ ⌈B^W + ratio(T')·T'⌉, ratio la courbe des cinq crans
(M, G calé à la participation de référence, inchangé). La règle d'Yvv du 03/11
(« Ils comptent comme non ») est seule dans threshold::judged_voters. Pour
l'écran : yes_needed (le total de pour qui passe avec les contre d'aujourd'hui)
et no_needed (le total de contre qui tient les pour d'aujourd'hui, 0 si le quorum
suffit) ; passe ⇔ pour ≥ yesNeeded ⇔ contre < noNeeded, éprouvé sur une grille.
well_rated : la part tient sur ceux qui sont venus. Scale porte les quorums par
cran, UnitState le quorum propre d'un article ; p0 reste 2·vote_floor/W.

Vu rouge : sans la règle (T' = T), 9 tests échouent ; avec l'autre lecture d'un
quorum (un minimum de votants, les absents non comptés), 8 échouent, dont « un
contre n'aide jamais ». Chiffres de contrôle (W 5 707, p0 = 100/W) tenus : 9, 39,
46 au quorum ; 7, 8, 9, 9, 10 à dix votants.

Le serveur suit au commit suivant.

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

crates/ld-engine/src/compose.rs

@@ -19,7 +19,8 @@
 //! - what the document would read if the well-rated, or all, proposals passed
 //!   (`preview`);
 //! - which formula a proposal is judged by (`params_for`): the level of
-//!   inertia of its unit, on the scale of its group (`inertia::Scale`).
+//!   inertia of its unit and its quorum, on the scale of its document
+//!   (`inertia::Scale`).
 
 use crate::inertia::{InertiaLevel, Scale};
 use crate::threshold::{FormulaParams, Tally, ThresholdError, evaluate};
@@ -40,6 +41,10 @@ pub struct UnitState {
     pub id: String,
     pub position: f64,
     pub inertia: InertiaLevel,
+    /// Its own quorum, set by the author of its first version before the first vote
+    /// (ADR 0013); `None`: the quorum of its level.
+    #[serde(default)]
+    pub quorum: Option<u32>,
     pub in_force: Option<VersionText>,
 }
 
@@ -84,8 +89,11 @@ pub fn voting_level(unit: &UnitState, kind: ProposalKind) -> InertiaLevel {
     }
 }
 
+/// The formula a proposal is judged by: the level it is voted at, and the quorum of its
+/// unit — its own, or that level's (a change of inertia inherits both).
 pub fn params_for(unit: &UnitState, kind: ProposalKind, scale: &Scale) -> FormulaParams {
-    scale.params(voting_level(unit, kind))
+    let level = voting_level(unit, kind);
+    scale.params(level, scale.quorum(level, unit.quorum))
 }
 
 /// A proposal that changes nothing cannot enter into force.
@@ -264,6 +272,7 @@ mod tests {
             id: id.into(),
             position,
             inertia: InertiaLevel::DEFAULT,
+            quorum: None,
             in_force: in_force.map(|b| VersionText {
                 id: format!("{id}-v"),
                 title: id.into(),
@@ -286,8 +295,9 @@ mod tests {
         }
     }
 
-    /// Monnaie libre before any median: W 5745, C 50, the reference p0 = 2C/W.
-    const SCALE: Scale = Scale { electorate: 5745, floor: 50.0, participation: 100.0 / 5745.0 };
+    /// Monnaie libre before any median: W 5745, the reference p0 = 2 × 50 / W, the quorums
+    /// 12 · 12 · 50 · 50 · 50 (ADR 0013).
+    const SCALE: Scale = Scale { electorate: 5745, participation: 100.0 / 5745.0, quorums: [12, 12, 50, 50, 50] };
 
     fn level(k: u8) -> InertiaLevel {
         InertiaLevel::new(k).expect("1 to 5")
@@ -301,12 +311,18 @@ mod tests {
     }
 
     #[test]
-    fn the_floor_holds_then_releases() {
+    fn the_quorum_holds_then_releases() {
+        // Level 3, quorum 50: under it the voters missing count as against, 39 « pour » pass.
         let units = [unit("E3", 7.0, None)];
-        let few = [prop("p1", "E3", ProposalKind::Text, "connaître", 49, 0)];
+        let few = [prop("p1", "E3", ProposalKind::Text, "connaître", 38, 0)];
         assert!(adoptions(&units, &few, &SCALE).expect("valid").is_empty());
-        let enough = [prop("p1", "E3", ProposalKind::Text, "connaître", 50, 0)];
+        let enough = [prop("p1", "E3", ProposalKind::Text, "connaître", 39, 0)];
         assert_eq!(adoptions(&units, &enough, &SCALE).expect("valid"), vec!["p1".to_string()]);
+        // Its own quorum, lower, set by its author: the same curve on fewer voters.
+        let mut own = unit("E3", 7.0, None);
+        own.quorum = Some(12);
+        let lower = [prop("p1", "E3", ProposalKind::Text, "connaître", 11, 0)];
+        assert_eq!(adoptions(&[own], &lower, &SCALE).expect("valid"), vec!["p1".to_string()]);
     }
 
     #[test]
@@ -339,7 +355,10 @@ mod tests {
             assert_eq!(voting_level(&u, kind), level(4), "inherits the level of the article");
             assert_eq!(params_for(&u, kind, &SCALE), params_for(&u, ProposalKind::Text, &SCALE));
         }
-        assert_eq!(params_for(&u, ProposalKind::Text, &SCALE).majority_pct, 60.0);
+        let p = params_for(&u, ProposalKind::Text, &SCALE);
+        assert_eq!((p.majority_pct, p.quorum), (60.0, 50), "the level, and so its quorum");
+        u.quorum = Some(20);
+        assert_eq!(params_for(&u, ProposalKind::Inertia(level(1)), &SCALE).quorum, 20, "and the article's own");
     }
 
     #[test]
@@ -358,7 +377,7 @@ mod tests {
         // The seed a minima has no vote: the first rival that reaches its threshold wins.
         let rival = [prop("r", "E1", ProposalKind::Text, "unicité reformulée", 50, 0)];
         assert_eq!(adoptions(&units, &rival, &SCALE).expect("valid"), vec!["r".to_string()]);
-        // A version in force by vote, margin 60 − 58 = 2: a rival at 55 (margin 55 − 54 = 1) waits.
+        // A version in force by vote, margin 60 − 47 = 13: a rival at 55 (margin 55 − 43 = 12) waits.
         if let Some(v) = units[0].in_force.as_mut() {
             v.tally = Tally { for_votes: 60, against: 0 };
         }