Merge branch 'dev' into agent/dex/CUB-30-put-filament-endpoint

backend/Program.cs

@@ -77,6 +77,10 @@ builder.Services.AddCors(options =>
 // ── SignalR (real-time printer updates) ────────────────────
 builder.Services.AddSignalR();
 
+// ── Health Checks ───────────────────────────────────────────
+builder.Services.AddHealthChecks()
+    .AddNpgSql(connectionString);
+
 var app = builder.Build();
 
 // ── Middleware ──────────────────────────────────────────────
@@ -93,6 +97,9 @@ app.MapControllers();
 // ── Hub Endpoints ───────────────────────────────────────────
 app.MapHub<PrinterHub>("/hubs/printer");
 
+// ── Health Check Endpoint ──────────────────────────────────
+app.MapHealthChecks("/health");
+
 app.Run();
 
 // Helper: builds a connection string from individual env vars.