Close Phase 4 overlay and Unix forwarding gaps

README.md

@@ -134,7 +134,9 @@ The bootstrap implementation provides:
   reads IPv4 packets from that interface, maps destination overlay IPs to
   imported peer cards, and routes packets over `/geth/overlay/1`. Creating the
   interface is explicit opt-in and may require `CAP_NET_ADMIN`, sudo, or
-  platform-specific network entitlements.
+  platform-specific network entitlements. Release archives include
+  `docs/overlay-platforms.md` with Linux TUN, macOS entitlement, and Windows
+  Wintun guidance.
 - `geth resource list`
 - `geth resource create <kind> <name>`
 - `geth keychain init [--admin-key <path>] [--signing-key <path>]`