conf: Make eval the recommended completion installation method

Changes:
- Removed all stderr output from completion command for clean eval
- Updated help text to recommend eval method as primary approach
- Kept file-based installation as alternative option

Help now shows:
  Quick setup (recommended):
    # Zsh - add to ~/.zshrc
    eval "$(conf completion zsh)"

  Persistent installation (alternative):
    conf completion zsh > ~/.oh-my-zsh/completions/_conf

Benefits:
- Silent output when eval-ed (no comments/messages)
- Simpler setup for users
- Works immediately without file management
- Still supports file-based installation for those who prefer it

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: neongreen

conf/cmd/main.go

@@ -572,47 +572,45 @@ var completionCmd = &cobra.Command{
 	Long: `Generate shell completion scripts with intelligent schema-aware suggestions.
 
 The completion system provides:
-- Configuration path completion from actual schemas 
+- Configuration path completion from actual schemas
 - Type-aware value suggestions (boolean, enum, etc.)
 - Current value display for existing settings
 - Descriptions for all configuration options
 
-Installation:
+Quick setup (recommended):
+  # Bash - add to ~/.bashrc
+  eval "$(conf completion bash)"
+
+  # Zsh - add to ~/.zshrc
+  eval "$(conf completion zsh)"
+
+  # Fish - add to ~/.config/fish/config.fish
+  conf completion fish | source
+
+Persistent installation (alternative):
   # Bash
-  conf completion bash > /etc/bash_completion.d/conf
-  # or for user-only:
   conf completion bash > ~/.local/share/bash-completion/completions/conf
 
-  # Zsh  
+  # Zsh
   conf completion zsh > ~/.oh-my-zsh/completions/_conf
-  # or add to fpath and autoload
 
   # Fish
   conf completion fish > ~/.config/fish/completions/conf.fish
 
-Then restart your shell or source the completion file.`,
+After adding to your shell config, restart your shell or source the file.`,
 	Args: cobra.ExactArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
 		shell := args[0]
 		switch shell {
 		case "bash":
-			fmt.Fprintf(os.Stderr, "# conf schema-aware completion for bash\n")
-			fmt.Fprintf(os.Stderr, "# Generated by: conf completion bash\n")
-			fmt.Fprintf(os.Stderr, "# Install with: conf completion bash > ~/.local/share/bash-completion/completions/conf\n\n")
 			rootCmd.GenBashCompletion(os.Stdout)
 		case "zsh":
-			fmt.Fprintf(os.Stderr, "# conf schema-aware completion for zsh\n")
-			fmt.Fprintf(os.Stderr, "# Generated by: conf completion zsh\n")
-			fmt.Fprintf(os.Stderr, "# Install with: conf completion zsh > ~/.oh-my-zsh/completions/_conf\n\n")
 			rootCmd.GenZshCompletion(os.Stdout)
 		case "fish":
-			fmt.Fprintf(os.Stderr, "# conf schema-aware completion for fish\n")
-			fmt.Fprintf(os.Stderr, "# Generated by: conf completion fish\n")
-			fmt.Fprintf(os.Stderr, "# Install with: conf completion fish > ~/.config/fish/completions/conf.fish\n\n")
 			rootCmd.GenFishCompletion(os.Stdout, true)
 		default:
-			fmt.Printf("Unsupported shell: %s\n", shell)
-			fmt.Println("\nSupported shells: bash, zsh, fish")
+			fmt.Fprintf(os.Stderr, "Unsupported shell: %s\n", shell)
+			fmt.Fprintln(os.Stderr, "\nSupported shells: bash, zsh, fish")
 			os.Exit(1)
 		}
 	},