Add minimal process reports

internal/core/reporting/report.go

@@ -0,0 +1,34 @@
+package reporting
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"time"
+)
+
+type ProcessReport struct {
+	Phase          string     `json:"phase"`
+	Status         string     `json:"status"`
+	Operation      string     `json:"operation"`
+	TranscriptPath string     `json:"transcript_path"`
+	GlossaryPath   string     `json:"glossary_path"`
+	OutputPath     string     `json:"output_path,omitempty"`
+	Modules        []string   `json:"modules"`
+	StartedAt      time.Time  `json:"started_at"`
+	CompletedAt    *time.Time `json:"completed_at,omitempty"`
+	ErrorMessage   string     `json:"error_message,omitempty"`
+}
+
+func WriteProcessReport(path string, report ProcessReport) error {
+	payload, err := json.MarshalIndent(report, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal process report JSON: %w", err)
+	}
+	payload = append(payload, '\n')
+
+	if err := os.WriteFile(path, payload, 0o644); err != nil {
+		return fmt.Errorf("failed to write report JSON file %q: %w", path, err)
+	}
+	return nil
+}