feat(recipe): add read-only shell execution with user confirmation

Implement executeReadOnlyShell method to safely run whitelisted read-only commands,
prompting for user approval and integrating AI-suggested commands for filesystem context.

internal/recipe/runner.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -249,3 +250,104 @@ func createUnifiedPatch(changes []FileChange, patchPath string) error {
 	}
 	return nil
 }
+
+// executeReadOnlyShell — safe, whitelisted, read-only shell execution with user confirmation
+func (r *Runner) executeReadOnlyShell(step Step, previousResults []string) {
+	prompt := fmt.Sprintf(`You need additional context from the filesystem for this step.
+
+Recipe Overview:
+%s
+
+Previous step results:
+%s
+
+=== CURRENT STEP ===
+Objective: %s
+Instructions: %s
+
+Return ONLY a JSON array of read-only commands. Example:
+
+[
+  {
+    "command": "ls",
+    "args": ["-la"]
+  },
+  {
+    "command": "cat",
+    "args": ["README.md"]
+  }
+]
+
+Only use safe read-only commands from the allowed list.`,
+		r.Recipe.Overview,
+		strings.Join(previousResults, "\n\n---\n\n"),
+		step.Objective,
+		step.Instructions)
+
+	messages := []map[string]string{
+		{"role": "system", "content": "You are Grok, built by xAI. Precise expert programmer and refactoring assistant."},
+		{"role": "user", "content": prompt},
+	}
+
+	response := r.Client.Stream(messages, r.Model)
+	fmt.Println()
+
+	type ShellCommand struct {
+		Command string   `json:"command"`
+		Args    []string `json:"args"`
+	}
+
+	var cmds []ShellCommand
+	start := strings.Index(response, "[")
+	end := strings.LastIndex(response, "]") + 1
+	if start == -1 {
+		fmt.Println("   ⚠️  No valid read-only commands returned — skipping.")
+		return
+	}
+
+	if err := json.Unmarshal([]byte(response[start:end]), &cmds); err != nil {
+		fmt.Printf("   ⚠️  Could not parse commands: %v\n", err)
+		return
+	}
+
+	for _, cmd := range cmds {
+		fullCmd := cmd.Command
+		if len(cmd.Args) > 0 {
+			fullCmd += " " + strings.Join(cmd.Args, " ")
+		}
+
+		// Safety: must be in whitelist
+		allowed := false
+		for _, allowedCmd := range r.Recipe.AllowedShellCommands {
+			if strings.HasPrefix(cmd.Command, allowedCmd) {
+				allowed = true
+				break
+			}
+		}
+		if !allowed {
+			fmt.Printf("   ❌ Command not allowed: %s\n", cmd.Command)
+			continue
+		}
+
+		// User confirmation
+		fmt.Printf("   Grok wants to run: %s\n   Allow this command? [y/N] ", fullCmd)
+		var answer string
+		_, err := fmt.Scanln(&answer)
+		if err != nil {
+			return
+		}
+		if strings.HasPrefix(strings.ToLower(answer), "y") {
+			execCmd := exec.Command(cmd.Command, cmd.Args...)
+			execCmd.Dir = r.resolveWorkDir()
+			output, err := execCmd.CombinedOutput()
+			if err != nil {
+				fmt.Printf("   ❌ Failed: %v\n%s\n", err, string(output))
+			} else {
+				fmt.Printf("   ✅ Success\n%s\n", string(output))
+				previousResults = append(previousResults, fmt.Sprintf("Command output:\n%s", string(output)))
+			}
+		} else {
+			fmt.Println("   ❌ Cancelled by user.")
+		}
+	}
+}