Swoff - Offline Infrastructure

`fetchWithCache<T>(input, options?)`

From swoff/fetch/core.ts.

Param	Type	Description
`input`	`RequestInfo`	URL string or Request object
`options`	`FetchWithCacheOptions`	See below

Returns: Promise<{ response: Response & { json(): Promise<T> }, fromCache: boolean }>

All RequestInit fields are supported (method, body, headers, credentials, signal, etc.) plus:

Option	Type	Default	Description
`tags`	`string[]`	auto-generated from URL	Cache invalidation tags for this request
`auth`	`boolean`	`false`	Attach auth token via `withAuthHeaders()`
`queueOffline`	`boolean`	`true`	When offline, queue writes to IndexedDB
`invalidate`	`'auto' \| string[] \| false`	`'auto'`	Auto-invalidate cache tags after successful mutation
`type`	`'read' \| 'mutation'`	auto-detected	Override read/mutation detection
`strategy`	`'cache-first' \| 'network-first' \| 'stale-while-revalidate' \| 'cache-only' \| 'network-only' \| 'reactive'`	—	Override caching strategy per-request (highest priority)
`staleTime`	`number`	—	Override stale time in seconds (reactive-only)
`validateSuccess`	`(response: Response) => boolean \| Promise<boolean>`	`res.ok`	Custom mutation success check (e.g. when API returns 200 with `{ success: false }`)
`invalidateUrl`	`string`	the request URL	Override the URL used for auto-invalidation tags. Useful when mutation URL differs from cache tag URL.
`signal`	`AbortSignal`	—	AbortController signal for cancellation

Behavior:

Read vs mutation: GET/HEAD → read (cached). POST/PUT/DELETE/PATCH → mutation (pass through). Override with type: 'read' or type: 'mutation'.
Offline reads: returns cached response if available; throws if not cached. Abort check: if signal.aborted, throws AbortError before cache lookup.
Offline writes: queues to IndexedDB (when mutationQueue enabled). Replays on online event. Disable per-request with queueOffline: false.
Request batching + dedup: concurrent GETs to the same URL within a 50 ms window coalesce into one network request. After the batch window closes, in-flight requests are deduplicated (late arrivals piggyback on the active promise). Each caller receives a cloned response.
Auto-tags: when tagInvalidation enabled, tags derived from URL path for read requests.
Auto-invalidate: after a successful mutation, matching cache tags are invalidated. Mutation success is determined by response.ok by default, or validateSuccess if provided. The auto-invalidation target URL can be overridden with invalidateUrl.
Auth: when auth: true, attaches auth headers. Dispatches sw-auth-unauthorized on 401.
StaleTime: 3-tier resolution (per-request / route pattern / global default). Only affects reactive strategy.
Background refresh retry: failed refetches are retried with exponential backoff via a shared RetryConfig.