HttpClient.get_text now accepts etag/last_modified and sends
If-None-Match/If-Modified-Since; a 304 returns no body and the caller reuses
the cached parse. fetch_target recovers validators from the stale cache entry
(via new cache::read_raw, TTL-agnostic) and stores whatever the server emits.
Verified live: OpenCode/Cloudflare returns no ETag or Last-Modified on either
page, so the slots stay None, no headers go out, and 304 never fires. The
machinery is correct and ready for the day they add validators.
Go page (/workspace/{id}/go): parse three [data-slot=usage-item] frames
(Rolling/Weekly/Monthly) into usage percentages + computed resets_at from the
relative reset-duration text. Zen page (/workspace/{id}): parse
[data-slot=balance] b into remaining + currency unit. Add an offline unit test
against tmp/ captures. Fix pretty renderer (percent display, money format,
day-aware relative times). Update DESIGN.md, README, examples and config
template to the real wrk_ workspace ids.
