Refonte design : 4 humeurs, onboarding, sections avec boite a outils

- Systeme de themes adaptatifs : Peps (light chaud), Zen (light calme),
  Chagrine (dark violet), Grave (dark ambre) avec CSS custom properties
- Dashboard d'accueil orienté onboarding avec cartes-portes et teaser
  boite a outils
- SectionLayout reutilisable : liste + sidebar toolbox + status pills
  cliquables (En prepa / En vote / En vigueur / Clos)
- ToolboxVignette : vignettes Contexte / Tutos / Choisir / Demarrer
- Seed : Acte engagement certification + forgeron, Runtime Upgrade
  (decision on-chain), 3 modalites de vote (majoritaire, quadratique,
  permanent)
- Backend adapte SQLite (Uuid portable, 204 fix, pool conditionnel)
- Correction noms composants (pathPrefix: false), pinia/nuxt ^0.11

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

backend/app/routers/auth.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 import secrets
 from datetime import datetime, timedelta, timezone
 
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, HTTPException, Response, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.config import settings
@@ -133,11 +133,11 @@ async def get_me(
     return IdentityOut.model_validate(identity)
 
 
-@router.post("/logout", status_code=status.HTTP_204_NO_CONTENT)
+@router.post("/logout", status_code=status.HTTP_204_NO_CONTENT, response_class=Response, response_model=None)
 async def logout(
     db: AsyncSession = Depends(get_db),
     identity: DuniterIdentity = Depends(get_current_identity),
-) -> None:
+):
     """Invalidate the current session token.
 
     Note: get_current_identity already validated the token, so we know it exists.

backend/app/routers/decisions.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import uuid
 
-from fastapi import APIRouter, Depends, HTTPException, Query, status
+from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
@@ -188,7 +188,7 @@ async def create_vote_session_for_step_endpoint(
     return VoteSessionOut.model_validate(session)
 
 
-@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT)
+@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT, response_class=Response, response_model=None)
 async def delete_decision(
     id: uuid.UUID,
     db: AsyncSession = Depends(get_db),

backend/app/routers/documents.py

@@ -6,7 +6,7 @@ import difflib
 import logging
 import uuid
 
-from fastapi import APIRouter, Depends, HTTPException, Query, status
+from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
 from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
@@ -316,7 +316,7 @@ async def update_item(
     return DocumentItemOut.model_validate(item)
 
 
-@router.delete("/{slug}/items/{item_id}", status_code=status.HTTP_204_NO_CONTENT)
+@router.delete("/{slug}/items/{item_id}", status_code=status.HTTP_204_NO_CONTENT, response_class=Response, response_model=None)
 async def delete_item(
     slug: str,
     item_id: uuid.UUID,

backend/app/routers/mandates.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import uuid
 
-from fastapi import APIRouter, Depends, HTTPException, Query, status
+from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
@@ -124,7 +124,7 @@ async def update_mandate(
     return MandateOut.model_validate(mandate)
 
 
-@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT)
+@router.delete("/{id}", status_code=status.HTTP_204_NO_CONTENT, response_class=Response, response_model=None)
 async def delete_mandate(
     id: uuid.UUID,
     db: AsyncSession = Depends(get_db),