Refactor: Centralize template context using unified TemplateData struct

- Introduced models.TemplateData for shared user/context state
- Moved context construction logic into handlers/template_context.go
- Simplified helpers.TemplateContext to accept structured data
- Restored and organized template helper functions
- Updated affected handlers (main.go, draw_handler.go, notifications.go)
- Improved scalability and separation of concerns in template rendering

handlers/draw_handler.go

@@ -6,7 +6,6 @@ import (
 	"log"
 	"net/http"
 
-	"synlotto-website/handlers"
 	"synlotto-website/helpers"
 	"synlotto-website/models"
 )
@@ -19,7 +18,7 @@ func NewDraw(db *sql.DB) http.HandlerFunc {
 		context["Page"] = "new_draw"
 		context["Data"] = nil
 
-		tmpl := template.Must(template.New("").Funcs(handlers.TemplateFuncs()).ParseFiles(
+		tmpl := template.Must(template.New("").Funcs(helpers.TemplateFuncs()).ParseFiles(
 			"templates/layout.html",
 			"templates/topbar.html",
 			"templates/new_draw.html",