feat(auth): politique de complexite du mot de passe et flux de reinitialisation

Remplace la regle de longueur seule (12 caracteres) par une exigence de
composition (8 caracteres minimum, majuscule, minuscule, chiffre, caractere
special), non documentee dans les exigences officielles du projet, par une
regle explicite partagee entre le backend (validateur Pydantic) et le
frontend.

Ajoute un flux "mot de passe oublie" en libre-service, absent jusqu'ici :
jeton a usage unique hache en base (meme principe que les refresh tokens),
expirant a 15 minutes, envoye par email via un service SMTP (aiosmtplib,
Mailpit en dev), avec limitation de debit dediee et reponse generique pour
eviter l'enumeration des comptes.

Closes #87

apps/backend/app/api/deps.py

@@ -16,6 +16,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.config import Settings, get_settings
 from app.core.hashing import Argon2Hasher, build_hasher
+from app.core.mailer import Mailer, SmtpConfig
 from app.core.principal import Principal
 from app.core.roles import AccountKind, Role, has_at_least
 from app.core.security import TokenExpiredError, TokenInvalidError, TokenPolicy
@@ -24,13 +25,15 @@ from app.db.session import get_session
 from app.repositories.alert import AlertRepository
 from app.repositories.audit_log import AuditLogRepository
 from app.repositories.login_attempt import LoginAttemptRepository
+from app.repositories.password_reset_attempt import PasswordResetAttemptRepository
+from app.repositories.password_reset_token import PasswordResetTokenRepository
 from app.repositories.reading import ReadingRepository
 from app.repositories.recommendation import RecommendationRepository
 from app.repositories.refresh_token import RefreshTokenRepository
 from app.repositories.site import SiteRepository
 from app.repositories.user import UserRepository
 from app.services.alert import AlertService
-from app.services.auth import AuthService, LoginPolicy
+from app.services.auth import AuthService, LoginPolicy, PasswordResetPolicy
 from app.services.recommendation import RecommendationService
 from app.services.sensor import SensorService
 from app.services.site import SiteService
@@ -97,11 +100,27 @@ def get_client_ip(request: Request, settings: SettingsDep) -> str | None:
     return request.client.host if request.client else None
 
 
+def get_mailer(settings: SettingsDep) -> Mailer:
+    return Mailer(
+        SmtpConfig(
+            host=settings.smtp_host,
+            port=settings.smtp_port,
+            username=settings.smtp_username,
+            password=(
+                settings.smtp_password.get_secret_value() if settings.smtp_password else None
+            ),
+            use_tls=settings.smtp_use_tls,
+            from_address=settings.smtp_from_address,
+        )
+    )
+
+
 def get_auth_service(
     session: SessionDep,
     settings: SettingsDep,
     hasher: Annotated[Argon2Hasher, Depends(get_hasher)],
     token_policy: Annotated[TokenPolicy, Depends(get_token_policy)],
+    mailer: Annotated[Mailer, Depends(get_mailer)],
 ) -> AuthService:
     return AuthService(
         users=UserRepository(session),
@@ -118,6 +137,16 @@ def get_auth_service(
             max_failures_per_identifier=settings.login_max_failures_per_identifier,
         ),
         refresh_ttl=timedelta(seconds=settings.refresh_token_ttl_seconds),
+        reset_tokens=PasswordResetTokenRepository(session),
+        reset_attempts=PasswordResetAttemptRepository(session),
+        reset_policy=PasswordResetPolicy(
+            window_seconds=settings.password_reset_window_seconds,
+            max_requests_per_identifier=settings.password_reset_max_requests_per_identifier,
+            max_requests_per_ip=settings.password_reset_max_requests_per_ip,
+            token_ttl=timedelta(seconds=settings.password_reset_ttl_seconds),
+            frontend_reset_url=settings.frontend_reset_password_url,
+        ),
+        mailer=mailer,
     )