Add mail setup guide, remove calendar configs

Documents the full Outlook.com OAuth2 mail setup (rbw, Azure app registration,
GPG, mutt-oauth2, mbsync, msmtp, neomutt) for reinstall reference.
Removes vdirsyncer/khal configs and calsync alias.

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

MAIL_SETUP.md

@@ -0,0 +1,98 @@
+# Mail Setup
+
+Neomutt + mbsync + msmtp with OAuth2 for Outlook.com personal accounts.
+Config files are in the dotfiles repo — this covers the manual steps needed on a fresh install.
+
+## Packages
+
+```bash
+sudo dnf install rbw isync msmtp neomutt
+```
+
+## 1. rbw (Bitwarden CLI)
+
+```bash
+rbw config set email robharbaugh@outlook.com
+rbw config set base_url https://vault.bitwarden.com
+rbw login
+```
+
+## 2. Azure OAuth2 App Registration
+
+Do this once. The client ID and secret live in Bitwarden.
+
+1. Go to portal.azure.com — sign in with robharbaugh@outlook.com as a personal account
+2. Search **App registrations** → **New registration**
+3. Name: anything (e.g. `neomutt`)
+4. Supported account types: **Accounts in any organizational directory and personal Microsoft accounts**
+5. Redirect URI: **Web** → `http://localhost/`
+6. Click **Register**, copy the **Application (client) ID** → save to rbw as `outlook-oauth-client-id`
+7. **Certificates & secrets** → **New client secret** → copy the **Value** → save to rbw as `outlook-oauth-client-secret`
+8. **API permissions** → **Add a permission** → **APIs my organization uses** → **Office 365 Exchange Online**
+9. **Delegated permissions** → add: `IMAP.AccessAsUser.All`, `SMTP.Send`, `offline_access`
+
+## 3. GPG Key
+
+Check for an existing key first:
+
+```bash
+gpg --list-secret-keys
+```
+
+If none, generate one:
+
+```bash
+gpg --full-generate-key
+```
+
+Choose RSA 4096, no expiry, use robharbaugh@outlook.com as the email.
+Note the short key ID (e.g. `A40B4F53`) — update the keychain line in `.zshrc` with it:
+
+```zsh
+eval "$(keychain --eval --quiet --gpg <key-id> github git)"
+```
+
+## 4. OAuth2 Token
+
+```bash
+mkdir -p ~/.config/neomutt
+export GPG_TTY=$(tty)
+python3 /usr/share/neomutt/oauth2/mutt_oauth2.py \
+  ~/.config/neomutt/outlook.tokens \
+  --authorize \
+  --provider microsoft \
+  --authflow localhostauthcode \
+  --encryption-pipe "gpg --encrypt --recipient robharbaugh@outlook.com" \
+  --decryption-pipe "gpg --decrypt" \
+  --client-id "$(rbw get outlook-oauth-client-id)" \
+  --client-secret "$(rbw get outlook-oauth-client-secret)"
+```
+
+Enter `robharbaugh@outlook.com` when prompted for email and GPG recipient.
+This opens a browser for the one-time Microsoft login. Tokens are saved to
+`~/.config/neomutt/outlook.tokens` (encrypted, not in git).
+
+## 5. Stow configs
+
+```bash
+cd ~/.dotfiles
+stow laptop
+```
+
+This symlinks mbsync, msmtp, neomutt, and all other configs into place.
+
+## 6. Initial mail sync
+
+```bash
+mkdir -p ~/mail/outlook ~/.local/share/msmtp
+mbsync
+```
+
+The first sync will take a while depending on mailbox size.
+
+## Token file
+
+`~/.config/neomutt/outlook.tokens` is managed by mutt-oauth2 and is not in git.
+It is GPG-encrypted with your key. If it is lost, re-run step 4.
+Tokens refresh automatically — you should never need to re-authorize unless
+you revoke the app in Azure.