Sprint 1 : scaffolding complet de Glibredecision

Plateforme de decisions collectives pour Duniter/G1.
Backend FastAPI async + PostgreSQL (14 tables, 8 routers, 6 services,
moteur de vote avec formule d'inertie WoT/Smith/TechComm).
Frontend Nuxt 4 + Nuxt UI v3 + Pinia (9 pages, 5 stores).
Infrastructure Docker + Woodpecker CI + Traefik.
Documentation technique et utilisateur (15 fichiers).
Seed : Licence G1, Engagement Forgeron v2.0.0, 4 protocoles de vote.
30 tests unitaires (formules, mode params, vote nuance) -- tous verts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/engine/threshold.py

@@ -0,0 +1,85 @@
+"""WoT members threshold formula for binary votes.
+
+Core formula:
+    Result = C + B^W + (M + (1-M) * (1 - (T/W)^G)) * max(0, T - C)
+
+Where:
+    C = constant_base
+    B = base_exponent
+    W = wot_size (corpus of eligible voters)
+    T = total_votes (for + against)
+    M = majority_ratio (majority_pct / 100)
+    G = gradient_exponent
+
+Inertia behaviour:
+    - Low participation (T << W) -> near-unanimity required
+    - High participation (T -> W) -> simple majority M suffices
+
+Reference test case:
+    wot_size=7224, votes_for=97, votes_against=23 (total=120)
+    params M50 B.1 G.2 => threshold=94, adopted (97 >= 94)
+"""
+
+from __future__ import annotations
+
+import math
+
+
+def wot_threshold(
+    wot_size: int,
+    total_votes: int,
+    majority_pct: int = 50,
+    base_exponent: float = 0.1,
+    gradient_exponent: float = 0.2,
+    constant_base: float = 0.0,
+) -> int:
+    """Compute the minimum number of *for* votes required for adoption.
+
+    Parameters
+    ----------
+    wot_size:
+        Size of the eligible voter corpus (WoT members).
+    total_votes:
+        Number of votes cast (for + against).
+    majority_pct:
+        Majority percentage (0-100). 50 = simple majority at full participation.
+    base_exponent:
+        B in the formula.  ``B^W`` contributes a vanishingly small offset
+        when W is large (0 < B < 1).
+    gradient_exponent:
+        G controls how fast the required super-majority decays toward M as
+        participation increases.
+    constant_base:
+        C, a fixed additive floor on the threshold.
+
+    Returns
+    -------
+    int
+        The ceiling of the computed threshold.  A vote passes when
+        ``votes_for >= wot_threshold(...)``.
+    """
+    if wot_size <= 0:
+        raise ValueError("wot_size doit etre strictement positif")
+    if total_votes < 0:
+        raise ValueError("total_votes ne peut pas etre negatif")
+    if not (0 <= majority_pct <= 100):
+        raise ValueError("majority_pct doit etre entre 0 et 100")
+
+    C = constant_base
+    B = base_exponent
+    W = wot_size
+    T = total_votes
+    M = majority_pct / 100.0
+    G = gradient_exponent
+
+    # Guard: if no votes, threshold is at least ceil(C + B^W)
+    if T == 0:
+        return math.ceil(C + B ** W)
+
+    # Core formula
+    participation_ratio = T / W
+    inertia_factor = 1.0 - participation_ratio ** G
+    required_ratio = M + (1.0 - M) * inertia_factor
+    result = C + B ** W + required_ratio * max(0.0, T - C)
+
+    return math.ceil(result)