refactor(recipe): improve error handling and restructure in runner

- Move FileChange struct to top-level for better organization.
- Enhance createUnifiedPatch with proper error handling on writes.
- Remove unused bufio import and update comments.
- Delete obsolete runner_test.go file.

internal/recipe/runner.go

@@ -1,7 +1,6 @@
 package recipe
 
 import (
-	_ "bufio"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -77,7 +76,7 @@ Execute this step now. Respond ONLY with the expected output format — no expla
 	return nil
 }
 
-// discoverFiles does a real filesystem scan
+// discoverFiles — temporary .go hard-code (we'll generalize with extensions next)
 func (r *Runner) discoverFiles() []string {
 	var files []string
 	root := "internal"
@@ -99,7 +98,11 @@ func (r *Runner) discoverFiles() []string {
 	return files
 }
 
-// handleApplyStep parses strict JSON from the refactor step — no regex at all
+type FileChange struct {
+	File    string `json:"file"`
+	Content string `json:"content"`
+}
+
 func (r *Runner) handleApplyStep(previousResults []string) {
 	if len(previousResults) == 0 {
 		fmt.Println("   ⚠️  No previous results to apply — skipping.")
@@ -118,11 +121,6 @@ func (r *Runner) handleApplyStep(previousResults []string) {
 
 	jsonStr := lastResult[start:end]
 
-	type FileChange struct {
-		File    string `json:"file"`
-		Content string `json:"content"`
-	}
-
 	var changes []FileChange
 	if err := json.Unmarshal([]byte(jsonStr), &changes); err != nil {
 		fmt.Printf("   ⚠️  Could not parse JSON: %v\n", err)
@@ -144,17 +142,28 @@ func (r *Runner) handleApplyStep(previousResults []string) {
 	fmt.Println("   Review it, then run with dry_run=false to apply.")
 }
 
-func createUnifiedPatch(changes []struct{ File, Content string }, patchPath string) error {
+func createUnifiedPatch(changes []FileChange, patchPath string) error {
 	f, err := os.Create(patchPath)
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer func(f *os.File) {
+		err := f.Close()
+		if err != nil {
+			return
+		}
+	}(f)
 
 	for _, ch := range changes {
-		fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", ch.File, ch.File, strings.Count(ch.Content, "\n")+1)
+		_, err := fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", ch.File, ch.File, strings.Count(ch.Content, "\n")+1)
+		if err != nil {
+			return err
+		}
 		for _, line := range strings.Split(ch.Content, "\n") {
-			fmt.Fprintf(f, "+%s\n", line)
+			_, err := fmt.Fprintf(f, "+%s\n", line)
+			if err != nil {
+				return err
+			}
 		}
 	}
 	return nil

internal/recipe/runner_test.go

@@ -1,61 +0,0 @@
-package recipe
-
-import (
-	"reflect"
-	"testing"
-)
-
-func TestExtractCodeBlocks(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name     string
-		input    string
-		expected map[string]string
-	}{
-		{
-			name:  "Single block",
-			input: "// main.go\n```go\npackage main\n\nfunc main() {}\n```",
-			expected: map[string]string{
-				"main.go": "package main\n\nfunc main() {}",
-			},
-		},
-		{
-			name: "Multiple blocks",
-			input: `// internal/utils.go
-` + "```" + `go
-package utils
-func Help() {}
-` + "```" + `
-Some commentary.
-// cmd/root.go
-` + "```" + `go
-package cmd
-func Execute() {}
-` + "```",
-			expected: map[string]string{
-				"internal/utils.go": "package utils\nfunc Help() {}",
-				"cmd/root.go":       "package cmd\nfunc Execute() {}",
-			},
-		},
-		{
-			name:     "No blocks",
-			input:    "Just some text without any blocks.",
-			expected: map[string]string{},
-		},
-		{
-			name:     "Incomplete block",
-			input:    "// oops.go\n```go\nfunc incomplete() {",
-			expected: map[string]string{},
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			got := extractCodeBlocks(tt.input)
-			if !reflect.DeepEqual(got, tt.expected) {
-				t.Errorf("extractCodeBlocks() = %v, want %v", got, tt.expected)
-			}
-		})
-	}
-}