Add Docker support and installation guide for easy server deployment

Includes a Dockerfile for building the application image and an INSTALLATION.md file detailing the setup process, prerequisites, and helpful commands for managing the application on a private server.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/ds3R7vP

client/src/components/topbar.tsx

@@ -0,0 +1,42 @@
+import { Bell, Menu } from "lucide-react";
+
+interface TopBarProps {
+  onMenuClick: () => void;
+}
+
+export default function TopBar({ onMenuClick }: TopBarProps) {
+  return (
+    <header className="bg-card border-b border-border sticky top-0 z-10">
+      <div className="flex items-center justify-between px-6 py-4">
+        <div className="flex items-center gap-4">
+          <button 
+            className="lg:hidden text-foreground"
+            onClick={onMenuClick}
+            data-testid="button-menu"
+          >
+            <Menu className="w-6 h-6" />
+          </button>
+          <div>
+            <h2 className="text-2xl font-bold text-foreground">Tableau de bord</h2>
+            <p className="text-sm text-muted-foreground">Gérez vos publications sur tous vos réseaux</p>
+          </div>
+        </div>
+        <div className="flex items-center gap-4">
+          <button className="relative p-2 text-muted-foreground hover:text-foreground transition-all" data-testid="button-notifications">
+            <Bell className="w-5 h-5" />
+            <span className="absolute top-1 right-1 w-2 h-2 bg-destructive rounded-full"></span>
+          </button>
+          <div className="flex items-center gap-3 pl-4 border-l border-border">
+            <div className="w-10 h-10 rounded-full bg-primary flex items-center justify-center">
+              <span className="text-primary-foreground font-semibold">SF</span>
+            </div>
+            <div className="hidden md:block">
+              <p className="text-sm font-medium text-foreground">Social Flow</p>
+              <p className="text-xs text-muted-foreground">admin@socialflow.app</p>
+            </div>
+          </div>
+        </div>
+      </div>
+    </header>
+  );
+}