fix: encode spaces in caldav URLs

[papatenko-bot]

Nextcloud hrefs embed the raw username. When the UID has a space, caldav's URL.join() keeps it and DAVObject.__init__ rejects the URL, breaking calendar reads and writes.

Changes

• calendar.py: quote the username in the calendar-home URL and patch caldav URL.join() to percent-encode joined paths
• tests: spaced usernames in the constructor, home-set discovery, and principal fallback paths

unquote() + quote() is idempotent, so already-encoded URLs are unaffected.

[CLAassistant]

All committers have signed the CLA.

[papatenko]

This primarily fixes the use case where user as a space within your username attempts to use the Calendar or other MCP tools.

Default User for example would cause the tool to not work before this change.

[cbcoutinho]

Hi @papatenko can you please add tests for this case? Spaces in usernames is a common source of strange bugs and is covered in other aspects of the codebase already

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[papatenko]

@cbcoutinho I added tests for it and narrowed down the scope of the bug fix to just CalDAV.

Calendar was the main issue to begin with; everything else works, except Contacts when using Claude Web. Here is the error I got from Claude:

list_addressbooks — server bug: crashes on an addressbook with a null display name (displayname Input should be a valid string). Contacts themselves are reachable if you know the URI slug.

Don't believe that is a result of the additions I made, but I could be wrong.