feat(web): real /about and /docs pages (unique crawlable content)

Addresses the top cross-engine AEO finding — every route previously served
the homepage SPA. /about and /docs are now distinct routes with their own
server-rendered content and titles.

- /about: substantive about page (what LogicSRC is, the standards surface,
  CommandBoard.run reference impl, GitHub, hire-us) — derived from public
  positioning, no fabricated team.
- /docs + /docs/[slug]: render the repo's docs/*.md (curated public set) via
  marked, statically generated at build (no runtime fs dependency).
- Drop about/docs from the catch-all; add doc URLs to the sitemap.

Verified in a running build: /about and /docs serve unique content with
distinct titles; /docs/[slug] renders each markdown doc.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/logicsrc-web/src/lib/docs.ts

@@ -0,0 +1,62 @@
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+
+// Repo-root docs/ (read at build time during static generation, so there is
+// no runtime filesystem dependency in the deployed image).
+const DOCS_DIR = resolve(process.cwd(), "../../docs");
+
+// Curated, public-facing reference docs. Internal notes (roadmap, positioning,
+// arcade) are intentionally excluded.
+export const DOC_SLUGS = [
+  "openspec-comparison",
+  "data-model",
+  "cli",
+  "tui",
+  "config",
+  "permissions",
+  "plugins",
+  "credential-sharing",
+  "agent-screening",
+] as const;
+
+export type DocSlug = (typeof DOC_SLUGS)[number];
+
+export function isDocSlug(slug: string): slug is DocSlug {
+  return (DOC_SLUGS as readonly string[]).includes(slug);
+}
+
+export function readDoc(slug: string): string | null {
+  if (!isDocSlug(slug)) return null;
+  try {
+    return readFileSync(resolve(DOCS_DIR, `${slug}.md`), "utf8");
+  } catch {
+    return null;
+  }
+}
+
+export function docTitle(markdown: string, slug: string): string {
+  const h1 = markdown.split("\n").find((line) => line.startsWith("# "));
+  return h1 ? h1.replace(/^#\s+/, "").trim() : slug;
+}
+
+export function docExcerpt(markdown: string): string {
+  for (const raw of markdown.split("\n")) {
+    const line = raw.trim();
+    if (line && !line.startsWith("#") && !line.startsWith("```") && !line.startsWith(">")) {
+      return line.replace(/[*_`#>[\]()]/g, "").trim().slice(0, 160);
+    }
+  }
+  return "";
+}
+
+export type DocSummary = { slug: DocSlug; title: string; excerpt: string };
+
+export function listDocs(): DocSummary[] {
+  const out: DocSummary[] = [];
+  for (const slug of DOC_SLUGS) {
+    const md = readDoc(slug);
+    if (!md) continue;
+    out.push({ slug, title: docTitle(md, slug), excerpt: docExcerpt(md) });
+  }
+  return out;
+}