refactor(api): streamline API requests with requestJson and requestBlob functions

Replaced direct fetch calls with requestJson and requestBlob utility functions across multiple components for improved consistency and error handling. This change enhances the maintainability of the codebase by centralizing API request logic and ensuring uniform handling of authentication and response parsing.

components/app-sidebar.tsx

@@ -38,6 +38,7 @@ import {
 } from "lucide-react"
 import { useDataSource } from "@/lib/data-source"
 import { useEvoBGP } from "@/lib/evobgp-context"
+import { requestJson } from "@/shared/api/http-client"
 import {
   formatSidebarBadgeCount,
   mockSidebarBadgesByUrl,
@@ -104,7 +105,7 @@ const navStructure: { label: string; items: NavItemBase[] }[] = [
 type LiveSidebarCounts = SidebarCountsDto & { greTunnels?: number; certificates?: number }
 
 export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
-  const { mode, backendUrl } = useDataSource()
+  const { mode, backendUrl, prefsHydrated } = useDataSource()
   const evo = useEvoBGP()
   const [mounted, setMounted] = React.useState(false)
   const [liveCounts, setLiveCounts] = React.useState<LiveSidebarCounts | null>(null)
@@ -118,30 +119,21 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
   }, [])
 
   React.useEffect(() => {
-    if (mode !== "live") {
-      setLiveCounts(null)
+    if (!prefsHydrated || mode !== "live") {
+      if (mode !== "live") setLiveCounts(null)
       return
     }
     let cancelled = false
     const load = async () => {
       try {
-        const base = backendUrl.replace(/\/$/, "")
-        const [cRes, gRes] = await Promise.all([
-          fetch(`${base}/api/sidebar-counts`),
-          fetch(`${base}/api/filters/gre-tunnels`),
+        const [cJson, gJson] = await Promise.all([
+          requestJson<SidebarCountsDto>(backendUrl, "/api/sidebar-counts"),
+          requestJson<{ tunnels?: unknown[] }>(backendUrl, "/api/filters/gre-tunnels").catch(
+            () => ({ tunnels: [] as unknown[] }),
+          ),
         ])
         if (cancelled) return
-        if (!cRes.ok) {
-          setLiveCounts(null)
-          return
-        }
-        const cJson = (await cRes.json()) as SidebarCountsDto
-        let greN = 0
-        if (gRes.ok) {
-          const gJson = (await gRes.json()) as { tunnels?: unknown[] }
-          greN = (gJson.tunnels ?? []).length
-        }
-        setLiveCounts({ ...cJson, greTunnels: greN })
+        setLiveCounts({ ...cJson, greTunnels: (gJson.tunnels ?? []).length })
       } catch {
         if (!cancelled) setLiveCounts(null)
       }
@@ -152,7 +144,7 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
       cancelled = true
       window.clearInterval(id)
     }
-  }, [mode, backendUrl])
+  }, [mode, backendUrl, prefsHydrated])
 
   const navGroups = React.useMemo((): NavGroup[] => {
     function badgeFor(url: string): string | undefined {

components/system-monitor-popover.tsx

@@ -9,6 +9,7 @@ import { cn } from "@/lib/utils"
 import { useDataSource } from "@/lib/data-source"
 import { filters, pingProbes, servers } from "@/lib/data"
 import type { SidebarCountsDto } from "@/lib/sidebar-badges"
+import { resolveApiUrl, requestJson } from "@/shared/api/http-client"
 
 type MonitorMetric = {
   id: string
@@ -78,11 +79,12 @@ function MetricCell({ metric }: { metric: MonitorMetric }) {
 
 /** Live system monitor popover — app-shell-7. @see https://reui.io/preview/base/app-shell-7 */
 export function SystemMonitorPopover() {
-  const { mode, backendUrl } = useDataSource()
+  const { mode, backendUrl, prefsHydrated } = useDataSource()
   const [healthOk, setHealthOk] = useState<boolean | null>(null)
   const [counts, setCounts] = useState<SidebarCountsDto | null>(null)
 
   useEffect(() => {
+    if (!prefsHydrated) return
     if (mode !== "live") {
       setHealthOk(true)
       setCounts({
@@ -98,11 +100,10 @@ export function SystemMonitorPopover() {
 
     let cancelled = false
     const load = async () => {
-      const base = backendUrl.replace(/\/$/, "")
       try {
-        const [hRes, cRes] = await Promise.all([
-          fetch(`${base}/health`),
-          fetch(`${base}/api/sidebar-counts`),
+        const [hRes, counts] = await Promise.all([
+          fetch(resolveApiUrl(backendUrl, "/health"), { signal: AbortSignal.timeout(3000) }),
+          requestJson<SidebarCountsDto>(backendUrl, "/api/sidebar-counts"),
         ])
         if (cancelled) return
         if (hRes.ok) {
@@ -111,11 +112,7 @@ export function SystemMonitorPopover() {
         } else {
           setHealthOk(false)
         }
-        if (cRes.ok) {
-          setCounts((await cRes.json()) as SidebarCountsDto)
-        } else {
-          setCounts(null)
-        }
+        setCounts(counts)
       } catch {
         if (!cancelled) {
           setHealthOk(false)
@@ -129,7 +126,7 @@ export function SystemMonitorPopover() {
       cancelled = true
       window.clearInterval(id)
     }
-  }, [mode, backendUrl])
+  }, [mode, backendUrl, prefsHydrated])
 
   const serversCount = counts?.servers ?? 0
   const filtersCount = counts?.filterRules ?? 0