Add Fastmail email and calendar, multi-account neomutt

- mbsync: add Fastmail IMAP channel (rbw for credentials)
- msmtp: add Fastmail SMTP account
- neomutt: add fastmail account file, F2/F3 account switching macros
- vdirsyncer + khal: Fastmail CalDAV calendar sync
- zshrc: restore calsync alias

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

laptop/.config/neomutt/accounts/personal

@@ -8,8 +8,9 @@ set postponed	=	+Drafts
 set trash	=	+Trash
 
 set signature	=	~/.config/neomutt/signature
-set sendmail	=	"/usr/bin/msmtp"
+set sendmail	=	"/usr/bin/msmtp -a outlook"
 set envelope_from = yes
 set sendmail_wait	=	0
 
+unmailboxes *
 mailboxes =Inbox =Drafts =Sent =Archive =Trash =Church =Family =House =Work =Notes