feat(adminsite): scaffold and site/'s token system

A fifth Next.js app, built like web/ and site/: App Router, React 18,
Tailwind 3, TanStack Query, standalone output.

app/globals.css carries site/app/globals.css's token blocks copied verbatim
rather than retyped, so the two cannot drift by transcription. Tailwind holds
var() references only -- no component or config entry may contain a hex
value. The semantic three are aliased: site/'s --up/--pend/--down become
valid/warn/expired, so each app names the colours for what it shows.

Unlike web/, there is no rewrite proxy: the browser calls admin directly, so
NEXT_PUBLIC_ADMIN_API_URL must be browser-reachable and listed in admin's
ADMIN_ORIGIN.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

adminsite/app/globals.css

@@ -0,0 +1,178 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+/* ==========================================================================
+   Vantage admin console design tokens.
+
+   Lines 8-97 below are site/app/globals.css's token blocks, copied verbatim:
+   the marketing site and this console are one visual system. Change them in
+   both apps in the same commit — nothing enforces the match automatically.
+
+   Light is the default because web/ is locked to dark, and telling the two
+   apart at a glance is what stops a Reissue landing in the wrong tab. In dark
+   mode the accent lifts to #5b9be8, which is nearer web/'s indigo, so the
+   distinction leans on the ground rather than the hue.
+   ========================================================================== */
+
+:root {
+    color-scheme: light dark;
+
+    --ground: #eaedf3;
+    --panel: #ffffff;
+    --panel-2: #f4f6fa;
+    --ink: #0a1b33;
+    --ink-2: #41556f;
+    --ink-3: #6c7f96;
+    --rule: #cdd6e2;
+    --rule-soft: #e0e6ef;
+    --accent: #0b2a58;
+    --accent-ink: #ffffff;
+    --up: #2f8a60;
+    --down: #c6462f;
+    --pend: #b0801f;
+    --shadow: 0 1px 0 rgba(10, 27, 51, 0.05), 0 18px 40px -26px rgba(10, 27, 51, 0.45);
+    --logo: #0b2a58;
+
+    --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
+    --mono: ui-monospace, "Cascadia Mono", "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
+
+    --s--1: clamp(0.76rem, 0.74rem + 0.1vw, 0.81rem);
+    --s-0: clamp(1rem, 0.97rem + 0.14vw, 1.05rem);
+    --s-1: clamp(1.16rem, 1.09rem + 0.32vw, 1.36rem);
+    --s-2: clamp(1.5rem, 1.34rem + 0.74vw, 2rem);
+    --s-3: clamp(2rem, 1.66rem + 1.6vw, 3.1rem);
+    --s-4: clamp(2.6rem, 1.9rem + 3.3vw, 4.9rem);
+
+    --rail: 1200px;
+}
+
+/* Dark tokens are defined once and applied through three selectors: the OS
+   preference, and both explicit values of data-theme so the in-page toggle
+   wins in either direction. */
+@media (prefers-color-scheme: dark) {
+    :root {
+        --ground: #071628;
+        --panel: #0d2138;
+        --panel-2: #102842;
+        --ink: #e4ecf6;
+        --ink-2: #9fb3ca;
+        --ink-3: #71879f;
+        --rule: #1e3855;
+        --rule-soft: #172c44;
+        --accent: #5b9be8;
+        --accent-ink: #04101f;
+        --up: #4fb484;
+        --down: #e2705a;
+        --pend: #d6a63f;
+        --shadow: 0 1px 0 rgba(0, 0, 0, 0.35), 0 20px 44px -26px rgba(0, 0, 0, 0.85);
+        --logo: #7fb2f0;
+    }
+}
+
+:root[data-theme="dark"] {
+    --ground: #071628;
+    --panel: #0d2138;
+    --panel-2: #102842;
+    --ink: #e4ecf6;
+    --ink-2: #9fb3ca;
+    --ink-3: #71879f;
+    --rule: #1e3855;
+    --rule-soft: #172c44;
+    --accent: #5b9be8;
+    --accent-ink: #04101f;
+    --up: #4fb484;
+    --down: #e2705a;
+    --pend: #d6a63f;
+    --shadow: 0 1px 0 rgba(0, 0, 0, 0.35), 0 20px 44px -26px rgba(0, 0, 0, 0.85);
+    --logo: #7fb2f0;
+}
+
+:root[data-theme="light"] {
+    --ground: #eaedf3;
+    --panel: #ffffff;
+    --panel-2: #f4f6fa;
+    --ink: #0a1b33;
+    --ink-2: #41556f;
+    --ink-3: #6c7f96;
+    --rule: #cdd6e2;
+    --rule-soft: #e0e6ef;
+    --accent: #0b2a58;
+    --accent-ink: #ffffff;
+    --up: #2f8a60;
+    --down: #c6462f;
+    --pend: #b0801f;
+    --shadow: 0 1px 0 rgba(10, 27, 51, 0.05), 0 18px 40px -26px rgba(10, 27, 51, 0.45);
+    --logo: #0b2a58;
+}
+
+/* Not in site/: the hatched sandbox badge and hover washes need a tinted fill,
+   and deriving it at each use would drift. */
+:root {
+    --accent-wash: rgba(11, 42, 88, 0.07);
+}
+
+@media (prefers-color-scheme: dark) {
+    :root {
+        --accent-wash: rgba(91, 155, 232, 0.1);
+    }
+}
+
+:root[data-theme="dark"] {
+    --accent-wash: rgba(91, 155, 232, 0.1);
+}
+
+:root[data-theme="light"] {
+    --accent-wash: rgba(11, 42, 88, 0.07);
+}
+
+*,
+*::before,
+*::after {
+    box-sizing: border-box;
+}
+
+body {
+    margin: 0;
+    background: var(--ground);
+    color: var(--ink);
+    font-family: var(--sans);
+    font-size: var(--s-0);
+    line-height: 1.6;
+    -webkit-font-smoothing: antialiased;
+}
+
+/* site/'s heading treatment, which is what replaces a display face. */
+h1,
+h2,
+h3 {
+    margin: 0;
+    font-weight: 800;
+    line-height: 1.03;
+    letter-spacing: -0.03em;
+    text-wrap: balance;
+}
+
+p {
+    margin: 0;
+}
+
+code {
+    font-family: var(--mono);
+    font-size: 0.92em;
+}
+
+:focus-visible {
+    outline: 2px solid var(--accent);
+    outline-offset: 3px;
+    border-radius: 2px;
+}
+
+@media (prefers-reduced-motion: reduce) {
+    *,
+    *::before,
+    *::after {
+        animation-duration: 0.001ms !important;
+        transition-duration: 0.001ms !important;
+    }
+}