Set personal git identity, fix zshrc theme, improve bw-ssh service

- config/git/gitconfig: real name, email, and SSH signing key
- config/shell/zshrc: fix typo 'powerlevel10zsh' → 'powerlevel10k'
- config/systemd/bw-ssh-keys.service: depend on graphical-session
  instead of network (ssh-agent starts with session); add explicit
  PATH so bw and jq are found; add RemainAfterExit=yes
  (avoids restart loop on oneshot services)

config/systemd/bw-ssh-keys.service

@@ -1,11 +1,13 @@
 [Unit]
 Description=Load Bitwarden SSH keys into ssh-agent
-After=network-online.target
-Wants=network-online.target
+After=graphical-session.target
+Wants=graphical-session.target
 
 [Service]
 Type=oneshot
+Environment=PATH=%h/.local/bin:/usr/local/bin:/usr/bin:/bin
 ExecStart=%h/.local/bin/bw-load-ssh.sh
+RemainAfterExit=yes
 Restart=on-failure
 RestartSec=30