Implement JWT authentication and app passkey support

- Add JWT token generation and validation
- Implement bcrypt password hashing
- Create auth service with register/login/refresh/logout
- Add app passkey generation and management
- Implement protected routes and auth middleware
- Add comprehensive tests for new functionality

go.mod

@@ -4,8 +4,11 @@ go 1.26.2
 
 require (
 	github.com/gin-gonic/gin v1.12.0
+	github.com/golang-jwt/jwt/v5 v5.3.1
+	github.com/google/uuid v1.6.0
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/viper v1.21.0
+	golang.org/x/crypto v0.48.0
 	gorm.io/driver/postgres v1.6.0
 	gorm.io/driver/sqlite v1.6.0
 	gorm.io/gorm v1.30.5
@@ -53,7 +56,6 @@ require (
 	go.mongodb.org/mongo-driver/v2 v2.5.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/arch v0.22.0 // indirect
-	golang.org/x/crypto v0.48.0 // indirect
 	golang.org/x/net v0.51.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.41.0 // indirect