Drop noisy spans and expected errors from Maple.layer

Maple.layer, the long-running preset in @maple-dev/effect-sdk, now accepts the span options that were only on MapleFlush.make and the Cloudflare make. All three presets take the same options and classify spans the same way.

• dropSpanNames drops spans by name prefix, as before. Only the matching span goes.
• dropSpanSubtrees drops a span and every span under it, so an idle polling loop and the queries it runs stop exporting. Outgoing calls under a dropped span carry an unsampled traceparent, and errors inside it are not tracked, so keep real work outside it.
• dropSpan takes a predicate on the finished span (name, kind, attributes, exit), for example to drop only polls that found nothing.
• anticipatedErrorIdentifiers marks expected failures (a duplicate, a not-found) as Ok with no exception, so they stop creating error groups. isAnticipatedError is its predicate form, for driver errors that are only expected in one case.
• excludeLogSpans is now available on Maple.layer too.

A few behaviour changes come with it:

• A server span that answered 5xx stays an error even when its failure is listed as anticipated.
• On Maple.layer, spans for unmatched-route 404s are dropped, and server spans that rendered a 5xx response are recorded as errors, matching the other presets. That can surface new error groups for crashes that used to export as Ok.

Upgrade to @maple-dev/effect-sdk 0.11.0.