feat: complete UI/UX overhaul with Impeccable design system

Replace Inter/Baskerville with self-hosted Manrope/Alegreya/JetBrains Mono
variable fonts. Migrate all colors from hex to OKLCH tokens (30+ CSS custom
properties) with full dark/light mode support. Replace Unicode emoji with
lucide-react SVG icons throughout. Convert all page layouts to inline styles
(Tailwind CSS 4 flex/grid classes unreliable in this project). Code-split
routes via React.lazy (760KB → 15KB initial shell + 10 lazy chunks).

Add global styles: scrollbar theming, selection color, input/button bases,
:focus-visible ring, prefers-reduced-motion. Setup wizard gets 4-phase
indicator with numbered circles, PathInput and StatusDot components.
Toast container gets aria-live="polite". Tab close buttons changed to
proper <button> elements with aria-labels.

All 8 pages (Dashboard, Editor, Build, Server, Toolset, Repos, Settings,
Setup) rewritten with consistent card/section/button patterns.

packages/frontend/tailwind.config.ts

@@ -9,16 +9,42 @@ export default {
         forge: {
           bg: "var(--forge-bg)",
           surface: "var(--forge-surface)",
+          "surface-raised": "var(--forge-surface-raised)",
           border: "var(--forge-border)",
           accent: "var(--forge-accent)",
+          "accent-hover": "var(--forge-accent-hover)",
+          "accent-subtle": "var(--forge-accent-subtle)",
+          "accent-text": "var(--forge-accent-text)",
           text: "var(--forge-text)",
           "text-secondary": "var(--forge-text-secondary)",
+          success: "var(--forge-success)",
+          "success-bg": "var(--forge-success-bg)",
+          "success-border": "var(--forge-success-border)",
+          danger: "var(--forge-danger)",
+          "danger-bg": "var(--forge-danger-bg)",
+          "danger-border": "var(--forge-danger-border)",
+          "danger-strong": "var(--forge-danger-strong)",
+          warning: "var(--forge-warning)",
+          "warning-bg": "var(--forge-warning-bg)",
+          "warning-border": "var(--forge-warning-border)",
+          info: "var(--forge-info)",
+          "info-bg": "var(--forge-info-bg)",
+          "log-bg": "var(--forge-log-bg)",
+          "log-text": "var(--forge-log-text)",
         },
       },
       fontFamily: {
-        sans: ["Inter", "system-ui", "sans-serif"],
-        mono: ["JetBrains Mono", "Fira Code", "monospace"],
-        serif: ["Baskerville", "Georgia", "Palatino", "serif"],
+        sans: ["Manrope Variable", "system-ui", "sans-serif"],
+        heading: ["Alegreya Variable", "Georgia", "serif"],
+        mono: ["JetBrains Mono Variable", "Fira Code", "monospace"],
+      },
+      fontSize: {
+        xs: "var(--text-xs)",
+        sm: "var(--text-sm)",
+        base: "var(--text-base)",
+        lg: "var(--text-lg)",
+        xl: "var(--text-xl)",
+        "2xl": "var(--text-2xl)",
       },
     },
   },