Initial open-source release (MIT): image2api AI gateway

Full Go backend + Vue 3 frontend, OpenAI-compatible API, multi-provider
account pools, billing/admin, Docker one-command deploy with auto HTTPS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/http/handler/health.go

@@ -0,0 +1,13 @@
+package handler
+
+import "github.com/gin-gonic/gin"
+
+type HealthHandler struct{}
+
+func NewHealthHandler() *HealthHandler {
+	return &HealthHandler{}
+}
+
+func (h *HealthHandler) Handle(c *gin.Context) {
+	c.JSON(200, gin.H{"ok": true})
+}