fix(web): CI E2E — resilient blog/RSS without Supabase + update stale test

The dynamic /blog/rss.xml returned 500 in CI (no Supabase env) and the E2E
still asserted the old static feed's hand-written items.

- /blog, /blog/[slug], and /blog/rss.xml now degrade gracefully (empty feed/
  list, HTTP 200) when Supabase is unavailable, instead of throwing.
- E2E: assert the always-present channel <title>LogicSRC Blog</title> and a
  looser xml content-type, dropping the removed static post titles.

Verified with `next dev` and no Supabase env (CI conditions): rss/blog/sitemap
all return 200.

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

apps/logicsrc-web/src/app/blog/rss.xml/route.ts

@@ -24,16 +24,22 @@ function escapeXml(value: string): string {
 }
 
 // GET /blog/rss.xml — RSS 2.0 feed generated from published blog_posts.
+// Degrades to an empty (but valid) feed when Supabase is unavailable.
 export async function GET(): Promise<Response> {
   const base = baseUrl();
-  const supabase = publicClient();
-  const { data } = await supabase
-    .from("blog_posts")
-    .select("slug, title, excerpt, published_at")
-    .eq("status", "published")
-    .order("published_at", { ascending: false })
-    .limit(50);
-  const posts = (data ?? []) as PostRow[];
+  let posts: PostRow[] = [];
+  try {
+    const supabase = publicClient();
+    const { data } = await supabase
+      .from("blog_posts")
+      .select("slug, title, excerpt, published_at")
+      .eq("status", "published")
+      .order("published_at", { ascending: false })
+      .limit(50);
+    posts = (data ?? []) as PostRow[];
+  } catch {
+    posts = [];
+  }
 
   const items = posts
     .map((post) => {