#84 footer: submit link points at POST-only /inbox/issue (405)

What

The new footer "submit" link (src/layout.rs:325) points at /inbox/issue, which is a POST-only endpoint.

• serve: GET /inbox/issue → 405
• static hosts/Pages: 404 or a Function rejection

The user-facing form is /new-issue.html.

Reproduced

curl -s -o /dev/null -w '%{http_code}\n' http://127.0.0.1:39320/inbox/issue
405

Impact

The only footer CTA is dead on every page.

Fix

Point the footer link at /new-issue.html (or the issues index) and leave /inbox/issue as the form action. Add a test for the footer href and a GET of the linked path in serve.