feat(recipe): add file discovery and special step handling in runner

- Introduce discoverFiles function to scan Go files in 'internal' for error handling patterns.
- Add special case for "discover" or "find" steps to perform filesystem scans.
- Refine LLM prompting to enforce strict output format and shorten system prompt.
- Update apply/patch handling and unified patch creation with simplifications.
- Import bufio for potential future use and adjust regex for code block extraction.

internal/recipe/runner.go

@@ -1,7 +1,7 @@
 package recipe
 
 import (
-	_ "bufio"
+	"bufio"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -29,14 +29,23 @@ func (r *Runner) Run() error {
 	for _, step := range r.Recipe.Steps {
 		fmt.Printf("Step %d/%d: %s\n", step.Number, len(r.Recipe.Steps), step.Title)
 
-		// Only special-case the Apply/Patch step (this is the only place the CLI needs to touch disk)
-		if strings.Contains(strings.ToLower(step.Title), "apply") || strings.Contains(strings.ToLower(step.Title), "patch") {
+		titleLower := strings.ToLower(step.Title)
+
+		// Only two special cases the CLI ever needs to handle
+		switch {
+		case strings.Contains(titleLower, "discover") || strings.Contains(titleLower, "find"):
+			files := r.discoverFiles()
+			result := strings.Join(files, "\n")
+			previousResults = append(previousResults, "Discovered files:\n"+result)
+			fmt.Println(result)
+
+		case strings.Contains(titleLower, "apply") || strings.Contains(titleLower, "patch"):
 			r.handleApplyStep(previousResults)
 			continue
-		}
 
-		// Everything else is pure LLM — the recipe defines exactly what to do
-		prompt := fmt.Sprintf(`Recipe Overview:
+		default:
+			// Everything else = pure LLM (works for any language)
+			prompt := fmt.Sprintf(`Recipe Overview:
 %s
 
 Previous step results (for context):
@@ -47,29 +56,52 @@ Objective: %s
 Instructions: %s
 Expected output format: %s
 
-Execute this step now.`,
-			r.Recipe.Overview,
-			strings.Join(previousResults, "\n\n---\n\n"),
-			step.Objective,
-			step.Instructions,
-			step.Expected)
+Execute this step now. Respond ONLY with the expected output format — no explanations, no extra text.`,
+				r.Recipe.Overview,
+				strings.Join(previousResults, "\n\n---\n\n"),
+				step.Objective,
+				step.Instructions,
+				step.Expected)
 
-		messages := []map[string]string{
-			{"role": "system", "content": "You are Grok, built by xAI. You are a precise, expert programmer and refactoring assistant. Always follow the user's instructions exactly for legitimate coding tasks."},
-			{"role": "user", "content": prompt},
+			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()
+
+			previousResults = append(previousResults, fmt.Sprintf("Step %d result:\n%s", step.Number, response))
 		}
-
-		response := r.Client.Stream(messages, r.Model)
-		fmt.Println()
-
-		previousResults = append(previousResults, fmt.Sprintf("Step %d result:\n%s", step.Number, response))
 	}
 
 	fmt.Println("\n✅ Recipe complete.")
 	return nil
 }
 
-// handleApplyStep is the ONLY place we touch the filesystem (exactly like edit/scaffold)
+// discoverFiles does a real filesystem scan — generic enough for any Go project
+func (r *Runner) discoverFiles() []string {
+	var files []string
+	root := "internal" // matches the recipe default; we can make it parametric later
+
+	_ = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
+		if err != nil || d.IsDir() || !strings.HasSuffix(path, ".go") {
+			return nil
+		}
+		b, _ := os.ReadFile(path)
+		if strings.Contains(string(b), "if err != nil") {
+			files = append(files, path)
+		}
+		return nil
+	})
+
+	if len(files) == 0 {
+		files = append(files, "No files found matching the criteria.")
+	}
+	return files
+}
+
+// handleApplyStep stays exactly as you had it (dry-run patch + confirmation)
 func (r *Runner) handleApplyStep(previousResults []string) {
 	if len(previousResults) == 0 {
 		fmt.Println("   ⚠️  No previous results to apply — skipping.")
@@ -84,7 +116,6 @@ func (r *Runner) handleApplyStep(previousResults []string) {
 		return
 	}
 
-	// Dry-run by default (we'll wire parameters later)
 	fmt.Println("   📄 Dry-run mode: creating patch file...")
 	patchPath := filepath.Join(".", "recipe-refactor.patch")
 	if err := createUnifiedPatch(blocks, patchPath); err != nil {
@@ -95,8 +126,7 @@ func (r *Runner) handleApplyStep(previousResults []string) {
 	fmt.Println("   Review it, then run with dry_run=false to apply.")
 }
 
-// Simple regex for the format the recipe asks Grok to return
-var blockRe = regexp.MustCompile(`(?s)//\s*(.+?\.go)\n` + "```" + `go\n(.*?)\n` + "```")
+var blockRe = regexp.MustCompile(`(?s)^//\s*(.+?\.go)\n```go\n(.*?)\n````)
 
 func extractCodeBlocks(text string) map[string]string {
 	blocks := make(map[string]string)
@@ -114,26 +144,12 @@ func createUnifiedPatch(blocks map[string]string, patchPath string) error {
 	if err != nil {
 		return err
 	}
-	defer func(f *os.File) {
-		err := f.Close()
-		if err != nil {
-			_, err := fmt.Fprintf(f, "+%s\n", err.Error())
-			if err != nil {
-				return
-			}
-		}
-	}(f)
+	defer f.Close()
 
 	for path, content := range blocks {
-		_, err := fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", path, path, strings.Count(content, "\n")+1)
-		if err != nil {
-			return err
-		}
+		fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", path, path, strings.Count(content, "\n")+1)
 		for _, line := range strings.Split(content, "\n") {
-			_, err := fmt.Fprintf(f, "+%s\n", line)
-			if err != nil {
-				return err
-			}
+			fmt.Fprintf(f, "+%s\n", line)
 		}
 	}
 	return nil