Ajoute une journalisation détaillée (login, mail, présence, rappels)

Niveau configurable via LOG_LEVEL (défaut DEBUG). Les erreurs de config
JSON invalide remontent maintenant un message clair (fichier + position)
au lieu d'un JSONDecodeError brut.

app/mail.py

@@ -1,11 +1,15 @@
 """Mail delivery via a configured SMTP relay (host/port/credentials in config.json)."""
+import logging
 import smtplib
 from email.mime.text import MIMEText
 
+logger = logging.getLogger("pointeuse.mail")
+
 
 def send_mail(to_addr: str, subject: str, body: str, from_addr: str, smtp_cfg: dict):
     host = smtp_cfg.get("host")
     if not host:
+        logger.error("envoi annulé: aucun serveur SMTP configuré (smtp.host manquant dans config.json)")
         raise RuntimeError("Aucun serveur SMTP configuré (smtp.host manquant dans config.json).")
     port = int(smtp_cfg.get("port", 587))
     user = smtp_cfg.get("user")
@@ -17,9 +21,21 @@ def send_mail(to_addr: str, subject: str, body: str, from_addr: str, smtp_cfg: d
     msg["From"] = from_addr
     msg["To"] = to_addr
 
-    with smtplib.SMTP(host, port, timeout=10) as smtp:
-        if use_tls:
-            smtp.starttls()
-        if user:
-            smtp.login(user, password)
-        smtp.send_message(msg)
+    logger.info(
+        "envoi mail: to=%r from=%r subject=%r via smtp=%s:%s user=%r tls=%r",
+        to_addr, from_addr, subject, host, port, user, use_tls,
+    )
+    try:
+        with smtplib.SMTP(host, port, timeout=10) as smtp:
+            smtp.set_debuglevel(1)
+            if use_tls:
+                logger.debug("STARTTLS vers %s:%s", host, port)
+                smtp.starttls()
+            if user:
+                logger.debug("login SMTP en tant que %r", user)
+                smtp.login(user, password)
+            smtp.send_message(msg)
+        logger.info("mail envoyé avec succès à %r", to_addr)
+    except Exception:
+        logger.exception("échec de l'envoi du mail à %r via %s:%s", to_addr, host, port)
+        raise