docs(recipes): add pwa offline boundary

Document optional PWA/offline support as an adapter boundary: cached shell, domain-command queues, server-canonical replay, conflict/fingerprint behavior, and sync-crate shape without adding a client state graph or service worker to core.

req: canonical_authoring/008

req: runtime/003

req: runtime/004

req: auth/002

req: auth/004

req: failure/004

req: failure/005

req: sync/001

req: sync/007

docs/v1-readiness.md

@@ -107,7 +107,7 @@ Remaining before GOAL_DONE:
 
 ### Production recipes
 
-Status: mostly satisfied; optional PWA/offline remains unresolved.
+Status: satisfied pending final recipe scan.
 
 Evidence:
 
@@ -116,12 +116,11 @@ Evidence:
 - observability/metrics + feature flags/killswitches:
   `docs/recipes/observability-flags.md`
 - deploy/versioning: `docs/recipes/deploy-versioning.md`
+- optional PWA/offline: `docs/recipes/pwa-offline.md`
 
 Remaining before GOAL_DONE:
 
-- Add a bounded optional PWA/offline recipe, or explicitly scope it out of v1 if
-  optional adapters are not required for the release.
-- Confirm whether SQLx/auth/observability/deploy recipes are sufficient as
+- Confirm whether SQLx/auth/observability/deploy/PWA recipes are sufficient as
   recipe-only production guidance or whether one provider path must be exercised
   by the tutorial crate before v1.
 
@@ -182,6 +181,5 @@ implementation path is a bounded, checked provider slice for `examples/saas`
 CI; the smallest docs path is an explicit release decision that the local adapter
 plus provider recipes is the v1 production boundary.
 
-After that, either add the optional PWA/offline recipe or explicitly scope it out
-of v1, then run the closure audit with the full gates from the active goal,
+After that, run the closure audit with the full gates from the active goal,
 including `cargo run -p hemx-xtask -- test` and the full diagnostics scan.