style: f-strings sans placeholder signalees par ruff (F541)

Aucun changement de comportement. Les chaines concernees ne contenaient
aucune substitution.

A noter pour plus tard : run_https.py conserve une banniere en caracteres
semi-graphiques, du meme type que celle qui faisait planter security_scan.py
sur une console Windows en cp1252. Le script n'etant lance qu'en
developpement et de facon explicite, le point est signale sans etre corrige
ici.

Co-Authored-By: Claude Opus 5 <[email protected]>

app/routes/auth.py

@@ -390,8 +390,8 @@ def discord_callback():
         token_response.raise_for_status()
         token_json = token_response.json()
         access_token = token_json.get('access_token')
-    except requests.RequestException as e:
-        flash(f'Failed to connect to Discord. Please try again.', 'danger')
+    except requests.RequestException:
+        flash('Failed to connect to Discord. Please try again.', 'danger')
         return redirect(url_for('auth.register'))
 
     if not access_token:

app/supporting_scripts/backup.py

@@ -148,7 +148,7 @@ def main():
     Returns:
         int: 0 on success, 1 on failure.
     """
-    print(f'=== Team Tryouts Backup ===')
+    print('=== Team Tryouts Backup ===')
     print(f'Started at: {datetime.now().strftime("%Y-%m-%d %H:%M:%S")}')
     print(f'Backup directory: {BACKUP_DIR}')
     print(f'Retention period: {BACKUP_RETENTION_DAYS} days')

app/supporting_scripts/run_https.py

@@ -107,13 +107,13 @@ def main():
     # Wrap the Flask app with the HTTPS middleware
     app.wsgi_app = ForceHTTPSMiddleware(app.wsgi_app)
 
-    print(f'\n╔══════════════════════════════════════════════════════╗')
-    print(f'║  TEAM TRYOUTS - Development HTTPS Server            ║')
-    print(f'╠══════════════════════════════════════════════════════╣')
+    print('\n╔══════════════════════════════════════════════════════╗')
+    print('║  TEAM TRYOUTS - Development HTTPS Server            ║')
+    print('╠══════════════════════════════════════════════════════╣')
     print(f'║  URL: https://{host}:{port}                      ║')
-    print(f'║  Cert: self-signed (accept browser warning)         ║')
-    print(f'║  Press Ctrl+C to stop                               ║')
-    print(f'╚══════════════════════════════════════════════════════╝\n')
+    print('║  Cert: self-signed (accept browser warning)         ║')
+    print('║  Press Ctrl+C to stop                               ║')
+    print('╚══════════════════════════════════════════════════════╝\n')
 
     # Create Waitress server with the SSL-wrapped socket
     server = create_server(