Replace direct Shiki usage with @pierre/diffs File component

Use the File component from @pierre/diffs/react instead of manually
creating a Shiki highlighter instance. Register the custom DOT grammar
via attachResolvedLanguages and drop the direct shiki dependency.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/arc-web/app/app.css

@@ -35,21 +35,6 @@
     radial-gradient(ellipse 80% 50% at 85% 90%, rgba(90, 200, 168, 0.07) 0%, transparent 45%);
   background-attachment: fixed;
 }
-/* ── Shiki syntax highlighting ── */
-
-.shiki-container pre.shiki {
-  background: transparent !important;
-  margin: 0;
-  padding: 1rem 1.25rem;
-  font-family: var(--font-mono);
-  font-size: 0.8125rem;
-  line-height: 1.7;
-}
-
-.shiki-container pre.shiki code {
-  font-family: inherit;
-}
-
 /* ── @pierre/diffs brand overrides ── */
 
 :root {

apps/arc-web/app/data/dot-grammar.ts

@@ -1,4 +1,4 @@
-import type { LanguageRegistration } from "shiki";
+import type { LanguageRegistration } from "@pierre/diffs";
 
 export const dotLanguage: LanguageRegistration = {
   name: "dot",

apps/arc-web/app/data/register-dot-language.ts

@@ -0,0 +1,17 @@
+import type { BundledLanguage } from "@pierre/diffs";
+import {
+  attachResolvedLanguages,
+  getSharedHighlighter,
+} from "@pierre/diffs";
+import { dotLanguage } from "./dot-grammar";
+
+export async function registerDotLanguage(): Promise<void> {
+  const highlighter = await getSharedHighlighter({
+    themes: ["pierre-dark"],
+    langs: [],
+  });
+  attachResolvedLanguages(
+    { name: "dot" as BundledLanguage, data: [dotLanguage] },
+    highlighter,
+  );
+}

apps/arc-web/app/routes/workflow-definition.tsx

@@ -1,94 +1,24 @@
-import { ChevronRightIcon } from "@heroicons/react/20/solid";
-import { useEffect, useRef, useState } from "react";
+import { useEffect, useState } from "react";
 import { useParams } from "react-router";
+import type { BundledLanguage } from "@pierre/diffs";
+import { File } from "@pierre/diffs/react";
+import { registerDotLanguage } from "../data/register-dot-language";
 import { workflowData } from "./workflow-detail";
-import { dotLanguage } from "../data/dot-grammar";
-
-function CodeBlock({
-  code,
-  lang,
-  filename,
-  defaultOpen = true,
-}: {
-  code: string;
-  lang: string;
-  filename: string;
-  defaultOpen?: boolean;
-}) {
-  const containerRef = useRef<HTMLDivElement>(null);
-  const [ready, setReady] = useState(false);
-  const [open, setOpen] = useState(defaultOpen);
-
-  useEffect(() => {
-    let cancelled = false;
-
-    async function highlight() {
-      const { createHighlighter } = await import("shiki");
-      if (cancelled) return;
-
-      const highlighter = await createHighlighter({
-        themes: ["nord"],
-        langs: lang === "dot" ? [dotLanguage] : [lang],
-      });
-
-      if (cancelled) return;
-
-      const html = highlighter.codeToHtml(code, {
-        lang,
-        theme: "nord",
-      });
-
-      if (cancelled || containerRef.current == null) return;
-      containerRef.current.innerHTML = html;
-      setReady(true);
-    }
-
-    highlight();
-    return () => {
-      cancelled = true;
-    };
-  }, [code, lang]);
-
-  const lines = code.split("\n");
-  const lineCount = lines.length;
-  const loc = lines.filter((l) => l.trim().length > 0).length;
-
-  return (
-    <div className="rounded-lg border border-white/[0.06] bg-navy-800/50 overflow-hidden">
-      <button
-        type="button"
-        onClick={() => setOpen((v) => !v)}
-        className="flex w-full items-center gap-2 px-4 py-2.5 text-left hover:bg-white/[0.02] transition-colors"
-      >
-        <ChevronRightIcon
-          className={`size-4 text-navy-600 transition-transform duration-150 ${open ? "rotate-90" : ""}`}
-        />
-        <span className="font-mono text-xs text-navy-600">{filename}</span>
-        <span className="ml-auto font-mono text-xs text-navy-600/60">
-          {lineCount} lines ({loc} loc)
-        </span>
-      </button>
-
-      <div className={open ? "" : "hidden"}>
-        <div className="border-t border-white/[0.06]" />
-        <div
-          ref={containerRef}
-          className={`shiki-container overflow-x-auto transition-opacity duration-200 ${ready ? "opacity-100" : "opacity-0"}`}
-        />
-
-        {!ready && (
-          <pre className="px-4 py-4 font-mono text-sm leading-relaxed text-navy-600">
-            {code}
-          </pre>
-        )}
-      </div>
-    </div>
-  );
-}
 
 export default function WorkflowDefinition() {
   const { name } = useParams();
   const workflow = workflowData[name ?? ""];
+  const [dotReady, setDotReady] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+    registerDotLanguage().then(() => {
+      if (!cancelled) setDotReady(true);
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
 
   if (workflow == null) {
     return <p className="text-sm text-navy-600">No configuration found.</p>;
@@ -96,8 +26,20 @@ export default function WorkflowDefinition() {
 
   return (
     <div className="flex flex-col gap-6">
-      <CodeBlock code={workflow.config} lang="toml" filename="task.toml" defaultOpen={false} />
-      <CodeBlock code={workflow.graph} lang="dot" filename={workflow.filename} />
+      <File
+        file={{ name: "task.toml", contents: workflow.config, lang: "toml" }}
+        options={{ theme: "pierre-dark" }}
+      />
+      {dotReady && (
+        <File
+          file={{
+            name: workflow.filename,
+            contents: workflow.graph,
+            lang: "dot" as BundledLanguage,
+          }}
+          options={{ theme: "pierre-dark" }}
+        />
+      )}
     </div>
   );
 }

apps/arc-web/package.json

@@ -18,8 +18,7 @@
     "isbot": "^5.1.31",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
-    "react-router": "7.12.0",
-    "shiki": "^4.0.0"
+    "react-router": "7.12.0"
   },
   "devDependencies": {
     "@react-router/dev": "7.12.0",