Unify installer colors with vim/shell palette and clean up output

- Replace BLUE/CYAN/CYAN_BOLD with TEAL/TEAL_BOLD (#2CB494) to match
  the primary accent used across vim, zsh prompt, tmux, and fzf
- Update BLUE (#0C48CC -> #4068D4) then merge into TEAL
- Update RED (#F40404 -> #F88C14) to match vim/shell error orange
- Rename GREEN to grey-blue (#7290B8) for [PASS] messages
- Format all raw echo output with log functions or log_quote
- Suppress sudo prompt when credentials are already cached
- Add missing log_pass to 22-zsh.sh and 23-stow.sh
- Convert raw 'already installed' echos to log_skip (7 scripts)
- Pipe SSH key and mise output through log_quote
- Suppress noisy bat cache and mise WARN output
- Match fastfetch colors to palette (teal logo, grey-blue keys)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

install.d/20-ssh.sh

@@ -23,7 +23,7 @@ if [ ! -f "$ssh_key" ]; then
         -C "$(whoami)@$(hostname)-$(date -I)"
 fi
 
-cat "$ssh_pub"
+cat "$ssh_pub" | log_quote
 
 unset ssh_method ssh_target ssh_key ssh_pub
 log_pass "SSH key configured"