feat : add frontend dashboard types and service

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/services/dto/dashboard.ts

@@ -0,0 +1,27 @@
+type DashboardEnvironment = {
+    id: number
+    name: string
+    status: string
+    version: string
+}
+
+type DashboardApplication = {
+    name: string
+    slug: string
+    giteaUrl?: string
+    environments: DashboardEnvironment[]
+}
+
+type DashboardResponse = {
+    applications: DashboardApplication[]
+}
+
+type EnvironmentHealth = {
+    status: string
+    version: string
+    startedAt: string
+    cpuPercent: number
+    memoryUsage: string
+    memoryLimit: string
+    memoryPercent: number
+}