feat: test-alert subcommand + enable email for bredelar.info

- Add `test-alert [--level yellow|red]` to verify SMTP without a real scan
- Enable email alerting in bredelar.info/config.yaml (uses DEFAULT_CONFIG
  for host/user/from/to, only smtp_password_env kept explicit)

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

bredelar.info/config.yaml

@@ -75,15 +75,8 @@ periodic_checks:
 alerting:
   min_level: "yellow"
   email:
-    enabled: false
-    smtp_host: "localhost"
-    smtp_port: 587
-    smtp_tls: true
-    smtp_user: ""
+    enabled: true
     smtp_password_env: "SCANNER_SMTP_PASSWORD"
-    from: "scanner@bredelar.info"
-    to:
-      - "admin@bredelar.info"
   webhook:
     enabled: false
     url: ""

scanner/__main__.py

@@ -1305,6 +1305,47 @@ def _print_summary(assessment: dict, diff: dict,
           f"Vollständiger Bericht:  python -m scanner report")
 
 
+def cmd_test_alert(args: argparse.Namespace, cfg: dict) -> int:
+    """Send a synthetic test alert to verify SMTP configuration."""
+    import os
+    level = args.level
+    target = cfg.get("target", "?")
+    email_cfg = cfg.get("alerting", {}).get("email", {})
+
+    if not email_cfg.get("enabled"):
+        print("E-Mail-Alarm ist in der config.yaml nicht aktiviert (alerting.email.enabled: false).")
+        return 1
+
+    pw_env = email_cfg.get("smtp_password_env", "SCANNER_SMTP_PASSWORD")
+    if not os.environ.get(pw_env):
+        print(f"Umgebungsvariable {pw_env} ist nicht gesetzt.")
+        print(f"Bitte in ~/.bashrc eintragen: export {pw_env}=\"Passwort\"")
+        return 1
+
+    report = {
+        "target": target,
+        "assessment": {
+            "level": level,
+            "score": 42 if level == "yellow" else 120,
+            "reasons": ["[TEST] Dies ist eine Test-Benachrichtigung des integrity-scanner."],
+            "exit_code": 1 if level == "yellow" else 2,
+        },
+        "diff": {
+            "new_external_domains": [],
+            "new_internal_urls": [],
+            "missing_internal_urls": [],
+            "page_diffs": [],
+            "new_broken_urls": [],
+            "known_broken_urls": [],
+        },
+    }
+
+    print(f"Sende Test-Alarm ({level}) an {email_cfg.get('to', [])} ...")
+    send_alert(report, cfg)
+    print("Fertig. Bitte E-Mail-Postfach prüfen.")
+    return 0
+
+
 # ---------------------------------------------------------------------------
 # Argument parser
 # ---------------------------------------------------------------------------
@@ -1350,6 +1391,12 @@ def _build_parser() -> argparse.ArgumentParser:
     aa = sub.add_parser("approve-assets", help="Aktuelle Asset-Hashes als neue Baseline setzen")
     aa.add_argument("--note", default="", help="Freitext-Notiz")
 
+    ta = sub.add_parser("test-alert", help="Test-E-Mail senden (prüft SMTP-Verbindung)")
+    ta.add_argument(
+        "--level", choices=["yellow", "red"], default="yellow",
+        help="Simulierter Alarm-Level (default: yellow)",
+    )
+
     return p
 
 
@@ -1436,6 +1483,7 @@ def main() -> None:
         "check-ext-links": cmd_check_ext_links,
         "check-assets": cmd_check_assets,
         "approve-assets": cmd_approve_assets,
+        "test-alert": cmd_test_alert,
     }
     handler = commands.get(args.command)
     if not handler: