feat: Initial OPHION structure

- Go backend with Fiber framework
- Agent for metrics collection
- Docker Compose for self-hosted
- Auth middleware (JWT + API Keys)
- Rate limiting
- Install script

internal/auth/middleware.go

@@ -0,0 +1,93 @@
+package auth
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"strings"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/golang-jwt/jwt/v5"
+)
+
+var jwtSecret []byte
+
+func Init(secret string) {
+	jwtSecret = []byte(secret)
+}
+
+// GenerateAPIKey creates a new API key for agents
+func GenerateAPIKey() string {
+	bytes := make([]byte, 32)
+	rand.Read(bytes)
+	return "ophion_" + hex.EncodeToString(bytes)
+}
+
+// GenerateJWT creates a JWT token for users
+func GenerateJWT(userID string, email string) (string, error) {
+	claims := jwt.MapClaims{
+		"sub":   userID,
+		"email": email,
+		"iat":   time.Now().Unix(),
+		"exp":   time.Now().Add(24 * time.Hour).Unix(),
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(jwtSecret)
+}
+
+// ValidateJWT validates a JWT token
+func ValidateJWT(tokenString string) (*jwt.MapClaims, error) {
+	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
+		return jwtSecret, nil
+	})
+
+	if err != nil || !token.Valid {
+		return nil, err
+	}
+
+	claims, ok := token.Claims.(jwt.MapClaims)
+	if !ok {
+		return nil, jwt.ErrInvalidKey
+	}
+
+	return &claims, nil
+}
+
+// AuthMiddleware protects routes
+func AuthMiddleware() fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		authHeader := c.Get("Authorization")
+		
+		if authHeader == "" {
+			return c.Status(401).JSON(fiber.Map{
+				"error": "Missing authorization header",
+			})
+		}
+
+		// Support both "Bearer <token>" and API keys
+		token := strings.TrimPrefix(authHeader, "Bearer ")
+		
+		// Check if it's an API key
+		if strings.HasPrefix(token, "ophion_") {
+			// TODO: Validate API key against database
+			c.Locals("auth_type", "api_key")
+			c.Locals("api_key", token)
+			return c.Next()
+		}
+
+		// Validate JWT
+		claims, err := ValidateJWT(token)
+		if err != nil {
+			return c.Status(401).JSON(fiber.Map{
+				"error": "Invalid token",
+			})
+		}
+
+		c.Locals("auth_type", "jwt")
+		c.Locals("user_id", (*claims)["sub"])
+		c.Locals("email", (*claims)["email"])
+		
+		return c.Next()
+	}
+}