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/nuanced_vote.py

@@ -0,0 +1,95 @@
+"""Six-level nuanced vote evaluation.
+
+Levels:
+    0 - CONTRE
+    1 - PAS DU TOUT
+    2 - PAS D'ACCORD
+    3 - NEUTRE
+    4 - D'ACCORD
+    5 - TOUT A FAIT
+
+Adoption rule:
+    The sum of votes at levels 3 + 4 + 5 must be >= threshold_pct% of total votes.
+    A minimum number of participants is also required.
+"""
+
+from __future__ import annotations
+
+LEVEL_LABELS: dict[int, str] = {
+    0: "CONTRE",
+    1: "PAS DU TOUT",
+    2: "PAS D'ACCORD",
+    3: "NEUTRE",
+    4: "D'ACCORD",
+    5: "TOUT A FAIT",
+}
+
+NUM_LEVELS = 6
+
+
+def evaluate_nuanced(
+    votes: list[int],
+    threshold_pct: int = 80,
+    min_participants: int = 59,
+) -> dict:
+    """Evaluate a nuanced vote from a list of individual vote levels.
+
+    Parameters
+    ----------
+    votes:
+        List of vote levels (each 0-5).  One entry per voter.
+    threshold_pct:
+        Minimum percentage of positive votes (levels 3-5) out of total
+        for adoption.
+    min_participants:
+        Minimum number of participants required for validity.
+
+    Returns
+    -------
+    dict
+        {
+            "total": int,
+            "per_level_counts": {0: int, 1: int, ..., 5: int},
+            "positive_count": int,       # levels 3 + 4 + 5
+            "positive_pct": float,        # 0.0 - 100.0
+            "threshold_met": bool,
+            "min_participants_met": bool,
+            "adopted": bool,
+        }
+
+    Raises
+    ------
+    ValueError
+        If any vote value is outside the 0-5 range.
+    """
+    # Validate vote levels
+    for v in votes:
+        if v < 0 or v > 5:
+            raise ValueError(
+                f"Niveau de vote invalide : {v}. Les niveaux valides sont 0-5."
+            )
+
+    total = len(votes)
+
+    per_level_counts: dict[int, int] = {level: 0 for level in range(NUM_LEVELS)}
+    for v in votes:
+        per_level_counts[v] += 1
+
+    # Positive = levels 3 (NEUTRE), 4 (D'ACCORD), 5 (TOUT A FAIT)
+    positive_count = per_level_counts[3] + per_level_counts[4] + per_level_counts[5]
+
+    positive_pct = (positive_count / total * 100.0) if total > 0 else 0.0
+
+    threshold_met = positive_pct >= threshold_pct
+    min_participants_met = total >= min_participants
+    adopted = threshold_met and min_participants_met
+
+    return {
+        "total": total,
+        "per_level_counts": per_level_counts,
+        "positive_count": positive_count,
+        "positive_pct": round(positive_pct, 2),
+        "threshold_met": threshold_met,
+        "min_participants_met": min_participants_met,
+        "adopted": adopted,
+    }