ai: scope console theme to content wrapper, fix font loading

Two bugs in the previous /ai redesign:

1. theme="console" on AppShell put the entire shell (sidebar, appbar,
   appbar dropdowns, the lot) inside [data-theme="console"], so the
   console palette + JetBrains Mono override leaked into the sidebar
   and made light mode look broken on /ai. Scoped now: the AppShell
   stays in skyrise (so light/dark toggle keeps working everywhere),
   and only the route content area gets data-theme="console" via an
   inner wrapper.

2. The Google Fonts @import inside console.css was being silently
   dropped because @import rules must precede all other rules in the
   final bundle, and skyrise's content lands first. Moved JetBrains
   Mono + Newsreader into app.css's top-level @import url() alongside
   the existing Inter/Instrument Sans/Geist Mono families.

Atmosphere ::before was also position: fixed, which painted the grain
overlay across the whole viewport (including the sidebar) regardless
of where data-theme lived. Now position: absolute on the wrapper, with
isolation: isolate to keep z-index local.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/app.css

@@ -1,4 +1,4 @@
-@import url("https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Instrument+Sans:ital,wght@0,400..700;1,400..700&family=Geist+Mono:wght@100..900&display=swap");
+@import url("https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Instrument+Sans:ital,wght@0,400..700;1,400..700&family=Geist+Mono:wght@100..900&family=JetBrains+Mono:ital,wght@0,400;0,500;0,600;0,700;1,400&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400&display=swap");
 
 /* Active theme — must be first so its @import url() font directives resolve
  * to the top of the output. Themes are self-contained: tokens + fonts. */

app/routes/ai.tsx

@@ -316,8 +316,15 @@ export default function AIRoute() {
   const availableModels = status.kind === "live" ? status.models : ["mock"]
 
   return (
-    <AppShell title="AI" theme="console">
+    <AppShell title="AI">
       <LLMProvider adapter={adapter} model={activeModel}>
+        {/* Console aesthetic is scoped to this wrapper only, so the appbar
+         * and sidebar keep using the global skyrise tokens (light/dark
+         * toggle still works for them). */}
+        <div
+          data-theme="console"
+          className="-m-6 flex h-full min-h-0 flex-col bg-[var(--console-ink)] text-[var(--console-text)]"
+        >
           <ChatSurface
             models={availableModels}
             model={activeModel}
@@ -328,6 +335,7 @@ export default function AIRoute() {
             isMock={status.kind === "mock"}
             onRetryProbe={probe}
           />
+        </div>
       </LLMProvider>
     </AppShell>
   )

app/themes/console.css

@@ -11,7 +11,9 @@
  * with skyrise / vibespace tokens.
  * ============================================================================ */
 
-@import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,500;0,600;0,700;1,400&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400&display=swap");
+/* Fonts (JetBrains Mono + Newsreader) are loaded by app.css's top-level
+ * @import url() — keep this file free of @import statements so it can sit
+ * inside the bundle without violating "@import before any rule". */
 
 [data-theme="console"] {
   /* ── Palette ─────────────────────────────────────────────────────────── */
@@ -90,10 +92,17 @@
     var(--console-ink);
 }
 
+/* Wrapper must be a positioning context so the grain overlay (and any
+ * other absolutely-positioned atmosphere) doesn't escape to the viewport. */
+[data-theme="console"] {
+  position: relative;
+  isolation: isolate;
+}
+
 /* Grain — single SVG turbulence, low opacity. Doesn't ship as an asset. */
 [data-theme="console"]::before {
   content: "";
-  position: fixed;
+  position: absolute;
   inset: 0;
   pointer-events: none;
   opacity: 0.035;