feat: add RSS feed for recent US Code updates (#132) (#134)

- /feed.xml endpoint using @astrojs/rss
- Shows 50 most recently updated sections
- Title format: "N U.S.C. § M — Section name"
- Feed autodiscovery link in BaseLayout head
- Enables RSS readers and monitoring tools to track changes

Closes #132

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

Author: williamzujkowski

apps/web/package.json

@@ -12,8 +12,9 @@
     "test": "vitest run"
   },
   "dependencies": {
-    "@civic-source/types": "workspace:*",
+    "@astrojs/rss": "^4.0.18",
     "@astrojs/svelte": "^8.0.4",
+    "@civic-source/types": "workspace:*",
     "@octokit/rest": "^22.0.1",
     "@tailwindcss/typography": "^0.5.19",
     "@tailwindcss/vite": "^4.2.2",

apps/web/src/layouts/BaseLayout.astro

@@ -38,6 +38,7 @@ const titleEntries = Object.entries(TITLE_NAMES)
     <link rel="canonical" href={new URL(Astro.url.pathname, Astro.site).href} />
     <meta name="base-url" content={base} />
     <link rel="icon" type="image/svg+xml" href={`${base}favicon.svg`} />
+    <link rel="alternate" type="application/rss+xml" title="US Code Tracker — Recent Updates" href={`${base}feed.xml`} />
     <!-- Open Graph -->
     <meta property="og:type" content="website" />
     <meta property="og:title" content={title === 'US Code Tracker' ? title : `${title} | US Code Tracker`} />

apps/web/src/pages/feed.xml.ts

@@ -0,0 +1,29 @@
+import rss from '@astrojs/rss';
+import { getCollection } from 'astro:content';
+import type { APIContext } from 'astro';
+
+export async function GET(context: APIContext) {
+  const statutes = await getCollection('statutes');
+
+  // Sort by generated_at descending to get most recently updated sections
+  const sorted = statutes
+    .filter(s => s.data.generated_at)
+    .sort((a, b) => {
+      const aDate = a.data.generated_at ?? '';
+      const bDate = b.data.generated_at ?? '';
+      return bDate.localeCompare(aDate);
+    })
+    .slice(0, 50);
+
+  return rss({
+    title: 'US Code Tracker — Recent Updates',
+    description: 'Track amendments to the United States Code. Updated weekly from the Office of the Law Revision Counsel.',
+    site: context.site ?? 'https://civic-source.github.io/us-code-tracker/',
+    items: sorted.map(entry => ({
+      title: `${entry.data.usc_title} U.S.C. § ${entry.data.usc_section} — ${entry.data.title.replace(/^Section \S+ - /, '')}`,
+      pubDate: new Date(entry.data.generated_at ?? Date.now()),
+      link: `/us-code-tracker/statute/${entry.id}/`,
+      description: `${entry.data.classification}. Current through ${entry.data.current_through}.`,
+    })),
+  });
+}