Class: RecoverablePromiseCache

BeNomad BeMap JavaScript API — RecoverablePromiseCache (v2.0) A drop-in replacement for pmtiles' `SharedPromiseCache` that FIXES the permanent-hole bug: the stock cache stores the header/directory *promise* and, when that promise REJECTS (a timeout / network blip / aborted read), leaves the rejected promise cached forever. Every dependent tile then awaits that cached rejection → a blank region until a full page reload. (`invalidate()` only runs on an `EtagMismatch`, never on a timeout/error.) This wrapper evicts a cache entry as soon as its promise rejects, so the NEXT read re-fetches instead of replaying the failure — self-healing without a reload. It is **transparent**: success, in-flight de-duplication, LRU pruning and `invalidate()` are all inherited unchanged (it delegates to a real `SharedPromiseCache`); the ONLY behavioural change is on a *failed* read. Composition (not subclassing) is deliberate: the bundled `pmtiles` is an ES6 UMD build whose `SharedPromiseCache` is an ES6 `class`, which cannot be `Function.apply`-ed for the ES5 subclass pattern this codebase uses. Composing a Cache-shaped object that delegates to an internal `SharedPromiseCache` (and deletes its internal entry on reject) is the portable, spec-matching form. Wire it via `new pmtiles.PMTiles(archiveUrl, new bemap.RecoverablePromiseCache())` + `protocol.add(...)` (see `bemap.MapLibreMap` — gated on `opts.recoverableCache`, default on). `bemap.MapLibreMap` does this automatically for the tiles archive.