Initial commit: Elydora Open Source — self-hosted audit platform for AI agents

Full self-hosted port of the Elydora tamper-evident audit protocol:
- Hono API server with PostgreSQL, Redis, MinIO adapters
- Ed25519 signed operations, chain hashing, Merkle epoch rollups
- PBKDF2 password hashing, HMAC-SHA256 JWT, 5-role RBAC
- Next.js management console
- Node.js, Python, and Go SDKs
- Docker Compose for local deployment
- Helm chart for Kubernetes
- Comprehensive security hardening and audit fixes applied

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sdks/go/cmd/elydora/plugins/jsonutil.go

@@ -0,0 +1,72 @@
+package plugins
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// expandHome replaces a leading ~ with the user's home directory.
+func expandHome(p string) (string, error) {
+	if !strings.HasPrefix(p, "~") {
+		return p, nil
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home directory: %w", err)
+	}
+	return filepath.Join(home, p[1:]), nil
+}
+
+// readJSONFile reads a JSON file into a map. Returns an empty map if the file does not exist.
+func readJSONFile(path string) (map[string]interface{}, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return make(map[string]interface{}), nil
+		}
+		return nil, fmt.Errorf("read %s: %w", path, err)
+	}
+	var result map[string]interface{}
+	if err := json.Unmarshal(data, &result); err != nil {
+		return nil, fmt.Errorf("parse %s: %w", path, err)
+	}
+	return result, nil
+}
+
+// writeJSONFile writes a map to a JSON file with indentation.
+func writeJSONFile(path string, data map[string]interface{}) error {
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return fmt.Errorf("create directory %s: %w", dir, err)
+	}
+	encoded, err := json.MarshalIndent(data, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshal json: %w", err)
+	}
+	encoded = append(encoded, '\n')
+	if err := os.WriteFile(path, encoded, 0644); err != nil {
+		return fmt.Errorf("write %s: %w", path, err)
+	}
+	return nil
+}
+
+// hookScriptPath returns the default path for the hook script inside ~/.elydora/<agentId>/.
+func hookScriptPath(agentId string) (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home directory: %w", err)
+	}
+	return filepath.Join(home, ".elydora", agentId, "hook.js"), nil
+}
+
+// guardScriptPath returns the default path for the guard script inside ~/.elydora/<agentId>/.
+func guardScriptPath(agentId string) (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home directory: %w", err)
+	}
+	return filepath.Join(home, ".elydora", agentId, "guard.js"), nil
+}