fix(web-server): correct caching headers for SHAs

This was introduced by 6e31cb249ee5b32d91f37ea516ca0f84bddc5aa9 when we switched to using SHA hashes rather than timestamps.
fix(reporter): remove SHAs from stack traces

Again, introduced by 6e31cb249ee5b32d91f37ea516ca0f84bddc5aa9.