fix(feed): add Atom link in emails page, fix HTML stripping, use request URL for self-link

- Add Atom Feed URL to the Feed Details card in the emails page
- Fix extractBodyContent to handle emails without a closing </body> tag
  (regex now falls back to capturing everything after the opening <body>)
- Use the actual request URL origin for atom:link rel="self" in RSS/Atom
  feeds, guaranteeing it always matches the document location regardless
  of how DOMAIN is configured

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/routes/rss.ts

@@ -16,11 +16,13 @@ export async function handle(c: Context<{ Bindings: Env }>): Promise<Response> {
     }
 
     const baseUrl = `https://${c.env.DOMAIN}`;
+    const selfUrl = new URL(c.req.url).origin + `/rss/${feedId}`;
     const rssXml = generateRssFeed(
       feedData.feedConfig,
       feedData.emails,
       baseUrl,
       feedId,
+      selfUrl,
     );
     const linkHeader = [
       `<${baseUrl}/hub>; rel="hub"`,