feat: smart zomboid traffic filtering with packet-size detection

Replace per-IP hashlimit with smarter filtering that distinguishes
legitimate players from scanner bots based on packet behavior:
- Players send varied packet sizes (53, 37, 1472 bytes)
- Scanners only send 53-byte query packets

New firewall rule chain:
- Priority 2: Mark + ACCEPT non-query packets (verifies player)
- Priority 3: ACCEPT queries from verified IPs (1 hour TTL)
- Priority 4: LOG rate-limited queries from unverified IPs
- Priority 5: DROP rate-limited queries (2 burst, then 1/hour)

Also includes:
- Fail2ban zomboid jail with tighter thresholds (5 retries/4h, 1w ban)
- Graylog streams for zomboid-connections, zomboid-ratelimit, fail2ban
- GeoIP pipeline enrichment for zomboid traffic
- Fluent-bit inputs for ratelimit logs and fail2ban events
- Remove Legendary Katana mod (Workshop 3418366499) - removed from Steam
- Bump Immich to v2.5.0
- Fix fulfillr config (nil → null)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ansible/roles/podman/templates/fulfillr/production.json.j2

@@ -10,7 +10,7 @@
   },
   "tax": {
     "ein": "{{ fulfillr_tax_ein }}",
-    "ioss": nil
+    "ioss": null
   },
   "sender_address": {
     "city": "Newbury",