The interceptor previously matched a strict `${HOSTED_FRONTEND_URL}/*`
prefix and did a naive String.replace, which broke whenever the backend
NEXT_FRONTEND_URL differed at all (apex vs www, http vs https, or a
self-hosted domain). Now:
- Match by host: apex + www. sibling, both http and https.
- Rewrite via URL parsing so only protocol/host change; query strings
containing the host as a value are left intact.
- Read HOSTED_FRONTEND_URL through getHostedFrontendUrl() which honors
a SURFSENSE_HOSTED_FRONTEND_URL_OVERRIDE env var, letting self-hosters
point their builds at their own frontend without rebuilding.
Default behavior is identical when override is unset and backend host
matches the baked-in value.
