feat(secrets-mcp): public home at /, login at /login (0.2.2)

Bump secrets-mcp to 0.2.2 and sync Cargo.lock.

Add home.html landing with SEO and footer link to the refining/secrets
repository; serve it at / and expose /login for sign-in.

Update OAuth error redirects and dashboard unauthenticated redirects to
/login. Improve login page meta tags, back-home link, and OAuth error
alert. Refresh llms.txt and robots.txt.

Made-with: Cursor

Cargo.lock

@@ -1968,7 +1968,7 @@ dependencies = [
 
 [[package]]
 name = "secrets-mcp"
-version = "0.2.1"
+version = "0.2.2"
 dependencies = [
  "anyhow",
  "askama",