feat(web): add automated build version tracking and update notification banner

Makefile

@@ -8,7 +8,7 @@ build: build-web build-server
 
 # Build the Go server
 build-server:
-	CGO_ENABLED=0 go build -o dumpster-server ./cmd/server
+	CGO_ENABLED=0 go build -ldflags "-X main.GitSHA=$(GIT_SHA)" -o dumpster-server ./cmd/server
 
 # Build the TUI client
 build-tui:

cmd/server/main.go

@@ -47,9 +47,8 @@ import (
 // @host localhost:8080
 // @BasePath /api/v1
 // @schemes http https
-// @securityDefinitions.apikey SessionAuth
-// @in cookie
-// @name dumpster_session
+var GitSHA = "dev"
+
 func main() {
 	logger := slog.New(slog.NewTextHandler(os.Stdout, nil))
 
@@ -153,6 +152,14 @@ func main() {
 
 	// API routes
 	r.Route("/api/v1", func(r chi.Router) {
+		r.Get("/version", func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+			json.NewEncoder(w).Encode(map[string]string{
+				"version": GitSHA,
+			})
+		})
+
 		// Auth (public: register, login, logout) with strict rate limiting
 		r.Route("/auth", func(r chi.Router) {
 			r.Use(middleware.RateLimit(5, 10)) // 5 req/s, burst 10

web/src/components/Layout.tsx

@@ -15,6 +15,7 @@ import { MemberList } from './MemberList.tsx';
 import { VoicePanel } from './VoicePanel.tsx';
 import { ServerSettingsModal } from './ServerSettingsModal.tsx';
 import { ThemeToggle } from './ThemeToggle.tsx';
+import { VersionNotifier } from './VersionNotifier.tsx';
 
 const STATUS_CYCLE: UserStatus[] = ['online', 'idle', 'dnd', 'offline'];
 function statusColor(status: UserStatus): string {
@@ -99,6 +100,7 @@ export function Layout() {
 
   return (
     <div className="h-full w-full bg-gb-bg text-gb-fg font-mono flex flex-col">
+      <VersionNotifier />
       {/* Outer terminal frame with safe area */}
       <div className="flex-1 terminal-border bg-gb-bg-h flex flex-col min-h-0"
         style={{ padding: 'var(--safe-top, 0.25rem) var(--safe-right, 0) var(--safe-bottom, 0) var(--safe-left, 0)' }}>

web/src/components/VersionNotifier.tsx

@@ -0,0 +1,58 @@
+import { useEffect, useState } from "react";
+import { api } from "../lib/api.ts";
+import { useWebSocketStore } from "../stores/ws.ts";
+
+export function VersionNotifier() {
+  const [serverVersion, setServerVersion] = useState<string | null>(null);
+  const [updateAvailable, setUpdateAvailable] = useState(false);
+  const connected = useWebSocketStore((s) => s.connected);
+
+  const checkVersion = async () => {
+    try {
+      const data = await api.get<{ version: string }>("/version");
+      if (data && data.version && data.version !== "dev") {
+        setServerVersion((prev) => {
+          if (!prev) {
+            return data.version;
+          }
+          if (prev !== data.version) {
+            setUpdateAvailable(true);
+          }
+          return data.version;
+        });
+      }
+    } catch {
+      // ignore check errors
+    }
+  };
+
+  useEffect(() => {
+    checkVersion();
+    const interval = setInterval(checkVersion, 2 * 60 * 1000); // Check every 2 mins
+    return () => clearInterval(interval);
+  }, []);
+
+  useEffect(() => {
+    if (connected) {
+      checkVersion();
+    }
+  }, [connected]);
+
+  const handleReload = () => {
+    window.location.reload();
+  };
+
+  if (!updateAvailable) return null;
+
+  return (
+    <div className="bg-gb-accent text-gb-bg-h px-4 py-2 text-xs font-semibold flex items-center justify-between shadow-lg z-50 animate-pulse">
+      <span>🚀 A new update is available! ({serverVersion})</span>
+      <button
+        onClick={handleReload}
+        className="bg-gb-bg-h text-gb-accent px-3 py-1 rounded hover:opacity-90 font-bold transition-all"
+      >
+        Update Now
+      </button>
+    </div>
+  );
+}