test(cli): fix stale group-email parse assertion

The M5.5 shared-group-secret work made a [group] [[triggers.email]] template
parse successfully (it materializes per descendant app; the inbound secret is
resolved against the group's own store server-side at apply). The unit test
still asserted the old parse-time rejection and had been failing on main under
`cargo test --workspace`. Update it to assert the current behavior: parse
accepts a group email template, like the group cron template above it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/picloud-cli/src/manifest.rs

@@ -904,13 +904,16 @@ mod tests {
         )
         .expect("group cron template parses");
         assert_eq!(cron.triggers.cron.len(), 1);
-        // ...but an email template on a group is still rejected (per-app secret).
-        let err = Manifest::parse(
+        // §4.5 M5.5: a group email template is now ALLOWED too — it materializes
+        // per descendant app and resolves its `inbound_secret_ref` against the
+        // GROUP's own secret store at apply (the server rejects it there if the
+        // secret is unset). Parse no longer refuses it.
+        let email = Manifest::parse(
             "[group]\nslug = \"acme\"\nname = \"ACME\"\n\n\
              [[triggers.email]]\nscript = \"shared\"\ninbound_secret_ref = \"sig\"\n",
         )
-        .expect_err("group email template is rejected");
-        assert!(err.to_string().contains("email"), "got: {err}");
+        .expect("group email template parses");
+        assert_eq!(email.triggers.email.len(), 1);
 
         // Neither / both is rejected.
         Manifest::parse("[vars]\nx = 1\n").expect_err("no [app] or [group]");