Extend the theme editor: typography, button/link colours, custom CSS, more presets

Grew /admin/theme from colours-only to a full theme editor, all applied
live via website_settings + ThemeVars:
- Typography: body font (10 web-safe + Google options; Google fonts load
  via an injected <link>) and H1/H2/H3 sizes (globals.css now reads
  --size-heading-* vars).
- Buttons & links: secondary/danger button colours + link/link-hover.
- Custom CSS: a raw textarea injected after the theme variables (staff-
  trusted), for anything the controls don't cover.
- Presets: 6 → 13 (added Galaxy, Royal, Cyberpunk, Neon, Coffee, Arctic,
  Christmas). ThemeVars now injects all the new vars + the font link.

Verified live (prod, amx_test): saved font=mono / H1=44px / custom CSS →
the public home reflected --font-family "Courier New", --size-heading-h1
44px and the injected rule; reverted the test settings. tsc 0,
vitest 49/49, next build 0.

src/lib/theme-presets.ts

@@ -1,6 +1,29 @@
 // Theme constants shared by the admin Theme page and its server action. Kept in
 // a plain module because a "use server" file may only export async functions.
 
+// Selectable body fonts. Web-safe stacks render with no extra request; the few
+// Google fonts load via a <link> ThemeVars injects when chosen.
+export const FONTS: Record<string, { label: string; stack: string; google?: string }> = {
+  nunito: { label: "Nunito (default)", stack: 'var(--font-nunito), "Nunito", sans-serif' },
+  system: { label: "System", stack: 'ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif' },
+  inter: {
+    label: "Inter",
+    stack: '"Inter", sans-serif',
+    google: "Inter:wght@400;600;700;800",
+  },
+  poppins: {
+    label: "Poppins",
+    stack: '"Poppins", sans-serif',
+    google: "Poppins:wght@400;600;700;800",
+  },
+  roboto: { label: "Roboto", stack: '"Roboto", sans-serif', google: "Roboto:wght@400;500;700" },
+  georgia: { label: "Georgia (serif)", stack: 'Georgia, "Times New Roman", serif' },
+  trebuchet: { label: "Trebuchet", stack: '"Trebuchet MS", Verdana, sans-serif' },
+  verdana: { label: "Verdana", stack: "Verdana, Geneva, sans-serif" },
+  comic: { label: "Comic (retro)", stack: '"Comic Sans MS", "Comic Sans", cursive' },
+  mono: { label: "Monospace", stack: '"Courier New", ui-monospace, monospace' },
+};
+
 // The colour settings ThemeVars injects into :root. Editing these recolours the
 // whole site live (ThemeVars reads them on every request).
 export const THEME_COLOR_KEYS = [
@@ -105,4 +128,102 @@ export const PRESETS: Record<string, Record<string, string>> = {
     button_text_color: "#ffffff",
     border_color: "#f472b6",
   },
+  Galaxy: {
+    color_primary: "#a855f7",
+    color_background: "#0b0a1f",
+    color_surface: "#171430",
+    color_dropdown: "#211d44",
+    color_navbar: "#171430",
+    color_navbar_text: "#e9e5ff",
+    color_text: "#e9e5ff",
+    color_text_muted: "#a39dcf",
+    color_accent: "#22d3ee",
+    button_primary_color: "#a855f7",
+    button_text_color: "#ffffff",
+    border_color: "#7c3aed",
+  },
+  Royal: {
+    color_primary: "#4f46e5",
+    color_background: "#f5f6ff",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#1e1b4b",
+    color_text: "#1e1b4b",
+    color_text_muted: "#636681",
+    color_accent: "#d97706",
+    button_primary_color: "#4f46e5",
+    button_text_color: "#ffffff",
+    border_color: "#818cf8",
+  },
+  Cyberpunk: {
+    color_primary: "#f0db4f",
+    color_background: "#0d0221",
+    color_surface: "#190933",
+    color_dropdown: "#241046",
+    color_navbar: "#190933",
+    color_navbar_text: "#f0db4f",
+    color_text: "#f5e9ff",
+    color_text_muted: "#b08fd6",
+    color_accent: "#ff2a6d",
+    button_primary_color: "#ff2a6d",
+    button_text_color: "#ffffff",
+    border_color: "#05d9e8",
+  },
+  Neon: {
+    color_primary: "#39ff14",
+    color_background: "#0a0a0a",
+    color_surface: "#141414",
+    color_dropdown: "#1d1d1d",
+    color_navbar: "#141414",
+    color_navbar_text: "#39ff14",
+    color_text: "#e8ffe8",
+    color_text_muted: "#7fae7f",
+    color_accent: "#ff00ff",
+    button_primary_color: "#39ff14",
+    button_text_color: "#0a0a0a",
+    border_color: "#39ff14",
+  },
+  Coffee: {
+    color_primary: "#a16207",
+    color_background: "#f5efe6",
+    color_surface: "#fffaf2",
+    color_dropdown: "#fffaf2",
+    color_navbar: "#fffaf2",
+    color_navbar_text: "#3f2d1c",
+    color_text: "#3f2d1c",
+    color_text_muted: "#8a7560",
+    color_accent: "#15803d",
+    button_primary_color: "#a16207",
+    button_text_color: "#ffffff",
+    border_color: "#ca8a04",
+  },
+  Arctic: {
+    color_primary: "#0891b2",
+    color_background: "#eef6fb",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#ffffff",
+    color_navbar_text: "#0e3a4f",
+    color_text: "#0e3a4f",
+    color_text_muted: "#5b7585",
+    color_accent: "#6366f1",
+    button_primary_color: "#0891b2",
+    button_text_color: "#ffffff",
+    border_color: "#67e8f9",
+  },
+  Christmas: {
+    color_primary: "#dc2626",
+    color_background: "#f4faf4",
+    color_surface: "#ffffff",
+    color_dropdown: "#ffffff",
+    color_navbar: "#0f3d24",
+    color_navbar_text: "#ffffff",
+    color_text: "#14321f",
+    color_text_muted: "#5f7a68",
+    color_accent: "#15803d",
+    button_primary_color: "#dc2626",
+    button_text_color: "#ffffff",
+    border_color: "#16a34a",
+  },
 };