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/errors.go

@@ -0,0 +1,26 @@
+package elydora
+
+import "fmt"
+
+// ElydoraError represents an error returned by the Elydora API.
+type ElydoraError struct {
+	StatusCode int
+	Code       ErrorCode              `json:"code"`
+	Message    string                 `json:"message"`
+	RequestID  string                 `json:"request_id"`
+	Details    map[string]interface{} `json:"details,omitempty"`
+}
+
+func (e *ElydoraError) Error() string {
+	return fmt.Sprintf("elydora: %s (code=%s, status=%d, request_id=%s)", e.Message, e.Code, e.StatusCode, e.RequestID)
+}
+
+// errorResponse is the wire format for API error responses.
+type errorResponse struct {
+	Error struct {
+		Code      ErrorCode              `json:"code"`
+		Message   string                 `json:"message"`
+		RequestID string                 `json:"request_id"`
+		Details   map[string]interface{} `json:"details,omitempty"`
+	} `json:"error"`
+}