Template private desktop mail configs

Render personal desktop configs from Ansible templates so public dotfiles no longer expose real identities or mail addresses. Update the bootstrap workflow to consume the rendered mail config and extend the encrypted vault schema for the new private values.

ansible/inventory/group_vars/desktop.yml

@@ -114,10 +114,6 @@ desktop_dotfiles:
     src: .xinitrc
     dest: .xinitrc
     mode: "0644"
-  - name: .gitconfig
-    src: .gitconfig
-    dest: .gitconfig
-    mode: "0644"
   - name: .gitignore_global
     src: .gitignore_global
     dest: .gitignore_global
@@ -126,14 +122,6 @@ desktop_dotfiles:
     src: .themes.gitignore
     dest: .themes.gitignore
     mode: "0644"
-  - name: .mbsyncrc
-    src: .mbsyncrc
-    dest: .mbsyncrc
-    mode: "0600"
-  - name: .msmtprc
-    src: .msmtprc
-    dest: .msmtprc
-    mode: "0600"
   - name: Emacs config
     src: .emacs.d/
     dest: .emacs.d/