feat: add Update Hermes and Restart Gateway action buttons to web dashboard

Implements the action button lifecycle described in #961:
- POST /api/actions/restart-gateway  — sends SIGTERM to the gateway PID
- POST /api/actions/update-hermes    — runs pip upgrade in a background job
- GET  /api/actions/jobs/{job_id}    — polls job status/output

Frontend (StatusPage.tsx):
- "Restart Gateway" button with spinning icon while running, then
  success/error message that clears after 5–8 s
- "Update Hermes" button that polls the job endpoint every 2 s;
  shows collapsible pip output on completion
- Page remains responsive (buttons disabled only during their own action)

Also adds i18n strings to en.ts, zh.ts, and the shared types.ts interface.

Fixes #961

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

web/src/lib/api.ts

@@ -426,3 +426,4 @@ export interface OAuthPollResponse {
   error_message?: string | null;
   expires_at?: number | null;
 }
+

web/src/pages/StatusPage.tsx

@@ -223,16 +223,13 @@ export default function StatusPage() {
               <RefreshCw className={`h-3.5 w-3.5 mr-1 ${restartState === "running" ? "animate-spin" : ""}`} />
               {restartState === "running" ? t.status.restarting : t.status.restartGateway}
             </Button>
-            {restartDetail && (
+            {(restartDetail || restartState === "success") && (
               <p className={`text-xs max-w-xs truncate ${restartState === "failure" ? "text-destructive" : "text-muted-foreground"}`}>
                 {restartState === "failure" && <TriangleAlert className="inline h-3 w-3 mr-1" />}
                 {restartState === "success" ? t.status.restartSuccess : restartState === "failure" ? t.status.restartFailed : ""}
                 {restartDetail && ` — ${restartDetail}`}
               </p>
             )}
-            {restartState === "success" && !restartDetail && (
-              <p className="text-xs text-muted-foreground">{t.status.restartSuccess}</p>
-            )}
           </div>
 
           {/* Update Hermes */}