Overhaul publication feeds, closes #195 #193 #183 #218 #156 #177 #194 #182

Adds enhanced publication feeds, offering both GeoRSS and Atom formats with regional filtering.

This change introduces a new, cached feed implementation with validation fixes, geometry filtering, and author attribution.
It also provides HTML pages for easy feed subscription.

- Implements global and regional publication feeds in GeoRSS and Atom formats.
- Adds caching to improve feed performance and reduce server load, with a configurable cache duration.
- Provides HTML pages for users to easily discover and subscribe to feeds.
- Introduces GeoRSS namespace declarations and validation fixes for standards compliance.
- Includes author and source information in feed entries.

The old feed URLs are redirected to the new API v1 endpoints for backwards compatibility.

Author: nuest

.claude/settings.local.json

@@ -13,9 +13,10 @@
       "Bash(python manage.py makemigrations:*)",
       "Bash(source:*)",
       "Bash(python manage.py shell:*)",
-      "Bash(python manage.py:*)"
+      "Bash(python manage.py:*)",
+      "Bash(python -m py_compile:*)"
     ],
     "deny": [],
     "ask": []
   }
-}
+}

optimap/settings.py

@@ -49,6 +49,9 @@
 
 DATA_DUMP_RETENTION = int(os.getenv("OPTIMAP_DATA_DUMP_RETENTION", 3))
 
+# Feed configuration
+FEED_CACHE_HOURS = int(os.getenv("OPTIMAP_FEED_CACHE_HOURS", 24))
+
 AUTHENTICATION_BACKENDS = [
     'django.contrib.auth.backends.ModelBackend',
     "sesame.backends.ModelBackend",