Add comprehensive tests and fix geomob URL bug

- Add complete test suite for geomob module (19 tests)
- Add comprehensive Bristol waste collection tests
- Fix geomob_email() double slash assertion bug for HTTPS URLs
- Fix utils.py human_readable_delta days pluralization
- Update agenda tests with better coverage

🤖 Generated with [Claude Code](https://claude.ai/code)

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

agenda/utils.py

@@ -71,7 +71,7 @@ def human_readable_delta(future_date: date) -> str | None:
     # Formatting the output
     parts = [
         plural(value, unit)
-        for value, unit in ((months, "month"), (weeks, "week"), (days, "days"))
+        for value, unit in ((months, "month"), (weeks, "week"), (days, "day"))
         if value > 0
     ]
     return " ".join(parts) if parts else None