dashy: add recent Falco alerts widget

Cron script (every 5m) pulls falco_rule_match raise transitions from
netdata's existing alert_transitions API - the same data already driving
the Telegram pipeline - and writes them as a Dashy custom-list JSON file.
No new containers/Redis/Falcosidekick needed for a quick-glance security
event feed on the dashboard.

conf.yml and the crontab entry live outside the repo (per existing
pattern) - conf.yml got a new custom-list widget block in the System
Widgets section, and crontab got a matching */5 entry alongside the
other host-cron jobs.

dashy/falco-alerts-to-dashy.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""Pull recent Falco alerts from netdata and write them as a Dashy
+custom-list JSON file, so the homelab dashboard shows a live feed of
+security events without needing Falcosidekick/Redis/a new UI.
+
+Run periodically via cron (see repo README/crontab entry). Reads from
+netdata's existing alert-transitions API - the same data already driving
+the Telegram pipeline - so this adds zero new attack surface or
+dependencies.
+"""
+import json
+import time
+import urllib.request
+
+NETDATA_URL = "http://192.168.1.67:19999"
+OUTPUT_PATH = "/srv/dashy/json-data/falco-alerts.json"
+LOOKBACK_SECONDS = 7 * 86400  # 7 days
+MAX_ENTRIES = 20
+
+
+def fetch_transitions():
+    now = int(time.time())
+    after = now - LOOKBACK_SECONDS
+    url = (
+        f"{NETDATA_URL}/api/v2/alert_transitions"
+        f"?after={after}&before={now}&last=500"
+    )
+    with urllib.request.urlopen(url, timeout=10) as resp:
+        return json.load(resp).get("transitions", [])
+
+
+def to_dashy_entry(t):
+    rule_name = t["summary"].removeprefix("Falco rule fired - ")
+    status = t["new"]["status"]
+    return {
+        "link": {
+            "text": "View",
+            "url": f"{NETDATA_URL}/",
+            "title": f"{status}: {rule_name}",
+        },
+        "value": {
+            "text": f"{status} - {rule_name}",
+            "title": "Falco",
+        },
+        "date": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(t["when"])),
+    }
+
+
+def main():
+    transitions = fetch_transitions()
+    raised = [
+        t
+        for t in transitions
+        if t.get("alert") == "falco_rule_match"
+        and t.get("new", {}).get("status") in ("WARNING", "CRITICAL")
+    ]
+    raised.sort(key=lambda t: t["when"], reverse=True)
+    entries = [to_dashy_entry(t) for t in raised[:MAX_ENTRIES]]
+
+    with open(OUTPUT_PATH, "w") as f:
+        json.dump(entries, f, indent=2)
+
+
+if __name__ == "__main__":
+    main()