Replace custom socket implementation with SignalR.

Replace MSAL and custom cookie auth with Microsoft.Identity.EntityFramework
Also some UI redesign to accommodate different login experience.

Shogi.UI/wwwroot/css/themes.css

@@ -0,0 +1,68 @@
+.PrimaryTheme {
+	--backgroundColor: #444444;
+	--foregroundColor: #eaeaea;
+	--hrefColor: #99c3ff;
+	--uniformBottomMargin: 0.5rem;
+	background-color: var(--backgroundColor);
+	color: var(--foregroundColor);
+	font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+}
+
+	.PrimaryTheme a {
+		color: var(--hrefColor);
+	}
+
+		.PrimaryTheme a:not(:hover) {
+			text-decoration: none;
+		}
+
+
+	.PrimaryTheme button {
+		background-color: var(--foregroundColor);
+		color: var(--backgroundColor);
+		border: none;
+		padding: 0.3rem 0.7rem;
+		border: 1px solid var(--backgroundColor);
+		border-radius: 2px;
+		cursor: pointer;
+		font: inherit;
+		font-size: 85%;
+	}
+
+		.PrimaryTheme button.href {
+			border: 0;
+			background: unset;
+			color: var(--hrefColor);
+			padding: 0;
+			font-size: 100%;
+		}
+
+			.PrimaryTheme button.href:hover {
+				text-decoration: underline;
+			}
+
+	.PrimaryTheme p, .PrimaryTheme h1, .PrimaryTheme h2, .PrimaryTheme h3, .PrimaryTheme h4, .PrimaryTheme h5, .PrimaryTheme h6 {
+		margin-top: 0;
+		margin-bottom: var(--uniformBottomMargin);
+	}
+
+	.PrimaryTheme ul {
+		padding: 0.3rem;
+		margin: 0;
+		margin-bottom: var(--uniformBottomMargin);
+		background-color: var(--foregroundColor);
+		color: var(--backgroundColor);
+		list-style-position: inside;
+	}
+
+
+
+	/***************************
+	*	    Contrast Variant     *
+	***************************/
+
+	.PrimaryTheme .ThemeVariant--Contrast {
+		--backgroundColor: #eaeaea;
+		--foregroundColor: #444444;
+		--hrefColor: #0065be;
+	}