Implemented the initial Go framework

internal/report/report.go

@@ -0,0 +1,64 @@
+package report
+
+import (
+	"encoding/json"
+	"os"
+)
+
+// Severity classifies report events.
+type Severity string
+
+const (
+	SeverityInfo      Severity = "info"
+	SeverityWarning   Severity = "warning"
+	SeverityCorrected Severity = "corrected"
+	SeverityError     Severity = "error"
+)
+
+// Event records a validation finding, correction, or pipeline action.
+type Event struct {
+	Severity Severity `json:"severity"`
+	Stage    string   `json:"stage"`
+	Module   string   `json:"module"`
+	Message  string   `json:"message"`
+}
+
+// Report is the deterministic report artifact emitted by the framework.
+type Report struct {
+	Metadata Metadata `json:"metadata"`
+	Events   []Event  `json:"events"`
+}
+
+// Metadata records the pipeline configuration that produced the report.
+type Metadata struct {
+	Application           string   `json:"application"`
+	Version               string   `json:"version"`
+	InputReader           string   `json:"input_reader"`
+	InputFiles            []string `json:"input_files"`
+	PreprocessingModules  []string `json:"preprocessing_modules"`
+	PostprocessingModules []string `json:"postprocessing_modules"`
+	OutputModules         []string `json:"output_modules"`
+}
+
+// Info constructs an informational report event.
+func Info(stage string, module string, message string) Event {
+	return Event{
+		Severity: SeverityInfo,
+		Stage:    stage,
+		Module:   module,
+		Message:  message,
+	}
+}
+
+// WriteJSON writes a deterministic JSON report.
+func WriteJSON(path string, rpt Report) error {
+	file, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	enc := json.NewEncoder(file)
+	enc.SetIndent("", "  ")
+	return enc.Encode(rpt)
+}