Licence EUPL-1.2 + hardening anti-abus

P1 — Licence :
- Ajout du fichier LICENSE (EUPL-1.2 complet)
- README mis à jour : section licence, table docs, vars d'environnement
- En-têtes EUPL ajoutés dans les fichiers sources principaux (Flask, React)

P2 — Hardening anti-abus :
- Rate limiting Redis-ready (REDIS_URL) avec clé fingerprint + IP
- Honeypot anti-bot : champ caché côté client + vérification serveur
- Fingerprinting non-PII via FingerprintJS (hash SHA-256, colonne ideas.fingerprint_hash)
- Cooldown session : cookie httpOnly signé HMAC-SHA256 (SECRET_KEY requis)
- Détection de flood : alerte WARNING si > FLOOD_THRESHOLD soumissions / 5 min
- hCaptcha stub : intégré, activable via HCAPTCHA_SECRET_KEY + VITE_HCAPTCHA_SITE_KEY
- Nouvelles dépendances : redis (backend), @fingerprintjs/fingerprintjs + @hcaptcha/react-hcaptcha (frontend)
- docs/SECURITE_ANTI_ABUS.md : documentation complète des seuils et de la configuration

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

artifacts/flask-api/database.py

@@ -1,5 +1,7 @@
 """
-Couche d'accès à la base de données PostgreSQL.
+La Voix du Peuple — Couche d'accès à la base de données PostgreSQL
+Copyright (C) 2026 billisdead — Licence EUPL-1.2
+
 Utilise psycopg2 directement — pas d'ORM, code lisible et transparent.
 """
 import os
@@ -32,7 +34,7 @@ def db_cursor():
         conn.close()
 
 
-def init_db():
+def init_db() -> None:
     """Crée les tables si elles n'existent pas, et applique les migrations nécessaires."""
     with db_cursor() as cur:
         cur.execute("""
@@ -46,10 +48,12 @@ def init_db():
                 created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
             )
         """)
+        # Migrations incrémentales — idempotentes
         cur.execute("ALTER TABLE ideas ADD COLUMN IF NOT EXISTS legal_basis TEXT")
         cur.execute("ALTER TABLE ideas ADD COLUMN IF NOT EXISTS flagged BOOLEAN NOT NULL DEFAULT FALSE")
         cur.execute("ALTER TABLE ideas ADD COLUMN IF NOT EXISTS flag_count INTEGER NOT NULL DEFAULT 0")
         cur.execute("ALTER TABLE ideas ADD COLUMN IF NOT EXISTS admin_note TEXT")
+        cur.execute("ALTER TABLE ideas ADD COLUMN IF NOT EXISTS fingerprint_hash VARCHAR(64)")
         cur.execute("""
             CREATE TABLE IF NOT EXISTS synthesis (
                 id SERIAL PRIMARY KEY,
@@ -61,16 +65,22 @@ def init_db():
     logger.info("Base de données initialisée.")
 
 
-def insert_idea(content: str, author: str | None, accepted: bool,
-                rejection_reason: str | None, legal_basis: str | None) -> dict:
+def insert_idea(
+    content: str,
+    author: str | None,
+    accepted: bool,
+    rejection_reason: str | None,
+    legal_basis: str | None,
+    fingerprint_hash: str | None = None,
+) -> dict:
     with db_cursor() as cur:
         cur.execute(
             """
-            INSERT INTO ideas (content, author, accepted, rejection_reason, legal_basis)
-            VALUES (%s, %s, %s, %s, %s)
+            INSERT INTO ideas (content, author, accepted, rejection_reason, legal_basis, fingerprint_hash)
+            VALUES (%s, %s, %s, %s, %s, %s)
             RETURNING *
             """,
-            (content, author, accepted, rejection_reason, legal_basis),
+            (content, author, accepted, rejection_reason, legal_basis, fingerprint_hash),
         )
         return dict(cur.fetchone())
 
@@ -91,8 +101,12 @@ def get_all_ideas(limit: int = 50) -> list[dict]:
         return [dict(row) for row in cur.fetchall()]
 
 
-def get_ideas_admin(status: str = "all", page: int = 1,
-                    per_page: int = 50, search: str = "") -> tuple[list[dict], int]:
+def get_ideas_admin(
+    status: str = "all",
+    page: int = 1,
+    per_page: int = 50,
+    search: str = "",
+) -> tuple[list[dict], int]:
     offset = (page - 1) * per_page
     conditions = []
     params: list = []
@@ -138,8 +152,12 @@ def bulk_delete_ideas(idea_ids: list[int]) -> int:
         return len(cur.fetchall())
 
 
-def override_idea(idea_id: int, accepted: bool,
-                  reason: str | None, note: str | None) -> dict | None:
+def override_idea(
+    idea_id: int,
+    accepted: bool,
+    reason: str | None,
+    note: str | None,
+) -> dict | None:
     with db_cursor() as cur:
         cur.execute(
             """