Add CardDAV supported-address-data, update vCards to 4.0 (#1948)

* Add CardDAV supported-address-data, update vCards to 4.0

- radicale/app/propfind.py: Add CS:getctag and CR:supported-address-data
  properties to VADDRESSBOOK collections in allprop responses; implement
  CR:supported-address-data handler that advertises vCard 4.0 as preferred
  format with 3.0 fallback per RFC 6352 section 6.2.2

- radicale/tests/static/contact1.vcf: Update from vCard 3.0 to 4.0 format

- radicale/tests/static/contact_multiple.vcf: Update both contact entries
  from vCard 3.0 to 4.0 format

- radicale/tests/static/contact_photo_with_data_uri.vcf: Update from vCard
  3.0 to 4.0 format; change PHOTO property from 3.0 syntax with ENCODING=b
  and TYPE parameters to 4.0 data URI syntax

* Conditionally offer vCard 4.0 based on vobject version

- Add vobject_supports_vcard4() helper function in utils.py
- Modify propfind.py to only advertise vCard 4.0 if vobject >= 1.0.0
- Add vCard 3.0 static test files for fallback testing
- Add tests for both vCard 3.0 and 4.0 contacts (v4 tests skipped if
  vobject < 1.0.0)
- Add propfind tests for CR:supported-address-data property

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

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

* Default vCard fixtures to v3.0, add explicit v4 files

- contact1.vcf: Change VERSION from 4.0 to 3.0 to make vCard 3.0 the default
  test fixture format, since vCard 3.0 is more widely supported

- contact1_v3.vcf: Delete file as contact1.vcf now serves as the v3.0 fixture

- contact1_v4.vcf: Add new file with VERSION 4.0 for explicit vCard 4.0
  testing with vobject >= 1.0.0

- contact_multiple.vcf: Change VERSION from 4.0 to 3.0 for both contacts to
  align with new default

- contact_multiple_v3.vcf: Delete file as contact_multiple.vcf now serves as
  the v3.0 fixture

- contact_multiple_v4.vcf: Add new file with VERSION 4.0 for both contacts

- contact_photo_with_data_uri.vcf: Change VERSION from 4.0 to 3.0 and update
  PHOTO property to use v3.0 format with ENCODING=b;TYPE=png parameters

- contact_photo_with_data_uri_v3.vcf: Delete file as
  contact_photo_with_data_uri.vcf now serves as the v3.0 fixture

- contact_photo_with_data_uri_v4.vcf: Add new file with VERSION 4.0 and v4.0
  PHOTO data URI format

- test_base.py: Update test methods to use renamed fixture files, with v3.0
  tests using default fixtures and v4.0 tests using explicit _v4.vcf files

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

radicale/utils.py

@@ -88,6 +88,17 @@ def package_version(name):
     return metadata.version(name)
 
 
+def vobject_supports_vcard4() -> bool:
+    """Check if vobject supports vCard 4.0 (requires version >= 1.0.0)."""
+    try:
+        version = package_version("vobject")
+        parts = version.split(".")
+        major = int(parts[0])
+        return major >= 1
+    except Exception:
+        return False
+
+
 def packages_version():
     versions = []
     versions.append("python=%s.%s.%s" % (sys.version_info[0], sys.version_info[1], sys.version_info[2]))