Add CrowdSec bouncer for Bunny CDN Shield

Syncs locally-detected CrowdSec ban decisions to Bunny CDN Shield
Access Lists. Excludes community blocklists (CAPI/lists) since Bunny
Shield has its own managed threat feeds.

- Polls CrowdSec LAPI for origin=crowdsec/cscli bans
- Updates Bunny Shield custom Access List via PATCH API
- Change detection via set comparison to skip unnecessary API calls
- Exponential backoff retry on API failures
- Graceful SIGTERM/SIGINT shutdown
- Docker healthcheck support

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

.env.example

@@ -0,0 +1,13 @@
+# CrowdSec LAPI connection
+CROWDSEC_LAPI_URL=http://crowdsec:8080
+CROWDSEC_LAPI_KEY=your_bouncer_api_key_here
+
+# Bunny CDN Shield API
+BUNNY_API_KEY=your_bunny_api_key_here
+BUNNY_SHIELD_ZONE_ID=12345
+BUNNY_ACCESS_LIST_ID=12345
+
+# Optional settings
+SYNC_INTERVAL=60
+MAX_IPS=1000
+LOG_LEVEL=INFO