Remove calendar tooling (vdirsyncer, khal, calsync)

Calendar handling left to phone. Mail-only setup going forward.

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

laptop/.config/khal/config

@@ -1,12 +0,0 @@
-[calendars]
-[[fastmail]]
-path = ~/.local/share/calendars/fastmail/*
-color = light blue
-
-[sqlite]
-path = ~/.local/share/khal/db.sqlite
-
-[locale]
-timeformat = %H:%M
-dateformat = %Y-%m-%d
-datetimeformat = %Y-%m-%d %H:%M

laptop/.config/vdirsyncer/config

@@ -1,18 +0,0 @@
-[general]
-status_path = "~/.local/share/vdirsyncer/status/"
-
-[pair fastmail_calendar]
-a = "fastmail_calendar_local"
-b = "fastmail_calendar_remote"
-collections = ["from a", "from b"]
-
-[storage fastmail_calendar_local]
-type = "filesystem"
-path = "~/.local/share/calendars/fastmail/"
-fileext = ".ics"
-
-[storage fastmail_calendar_remote]
-type = "caldav"
-url = "https://caldav.fastmail.com/dav/"
-username = "rob@rharbaugh.com"
-password.fetch = ["command", "rbw", "get", "fastmail-app-password"]