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/templates/desktop/.gitconfig.j2

@@ -0,0 +1,83 @@
+[init]
+  defaultBranch = main
+
+[core]
+  excludesfile = ~/.gitignore_global
+  pager = delta
+
+[user]
+  name = {{ vault_personal_full_name }}
+  email = {{ vault_git_email }}
+  signingkey = {{ vault_git_signing_key }}
+
+[fetch]
+  prune = true
+
+[remote "origin"]
+  prune = true
+
+[pull]
+  rebase = true
+
+[commit]
+  gpgsign = false
+
+[merge]
+  conflictstyle = diff3
+  tool = meld
+
+[mergetool]
+  prompt = false
+
+[diff]
+  tool = meld
+
+[color]
+  ui = always
+
+[color "status"]
+  branch = magenta
+  untracked = cyan
+  unmerged = yellow bold
+
+[color "diff"]
+  frag = magenta bold
+  old = red bold
+  new = green bold
+  whitespace = red reverse
+
+[color "diff-highlight"]
+  oldNormal = red bold
+  oldHighlight = red bold 52
+  newNormal = green bold
+  newHighlight = green bold 52
+
+[help]
+  autocorrect = 30
+
+[interactive]
+  diffFilter = delta --color-only
+
+[alias]
+  co = checkout
+  br = branch
+  ci = commit
+  st = status
+  ld = log -p
+  lg = log --graph --abbrev-commit --decorate --date=relative --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold yellow)%d%C(reset)%n' --all
+  glog = log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset'
+  onelinegraph = log --oneline --graph --decorate 
+  undo = reset --soft HEAD~1
+  stash-all = stash save --include-untracked
+  expireunreachablenow = reflog expire --expire-unreachable=now --all
+  gcunreachablenow = gc --prune=now 
+ 
+[include]
+  path = ~/.themes.gitignore
+
+[delta]
+  features = catppuccin-mocha navigate
+  true-color = always
+  colorMoved = default
+  tabs = 4
+  side-by-side = true