docs(changelog): note portal-rates fallback-only update in app/rest

Author: portal-wheatley

CHANGELOG.md

@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 #### Added
 - `MessageRouter` now exposes `SendOutcome` / `EventSendResult` from the underlying `portal` crate, giving relay delivery feedback per event. `SendOutcome::Delivered { relays }` includes the URLs of relays that accepted the event. Not yet surfaced on the REST API; wiring will follow in a future release (#85)
+- `portal-rates`: added fallback-only market source failover in `MarketAPI` (tries fallback providers when the primary source fails). No `fiatUnits` mapping changes in this update (#129).
 
 ---
 
@@ -100,6 +101,7 @@ First release — Docker image available at [`getportal/sdk-daemon`](https://hub
 
 #### Added
 - `MessageRouter::add_conversation`, `add_conversation_with_relays` and `add_and_subscribe` now return `Vec<EventSendResult>` alongside their existing values, pairing each broadcasted Nostr event ID with a `SendOutcome`. `Delivered { relays }` includes the list of relay URLs that accepted the event; `Queued` means no relay was available (event queued for retry); `Dropped` means the queue was full. Callers can now detect when a command is silently queued because no relay is connected (#85). Existing mobile app behavior is preserved — outcomes are currently ignored, ready to be wired into the UI when needed.
+- `portal-rates`: added fallback-only market source failover in `MarketAPI` (tries fallback providers when the primary source fails). No `fiatUnits` mapping changes in this update (#129).
 
 #### Changed
 - `register_nip05()` now delegates to `portal::register_nip05()` (moved to `portal` crate). UniFFI bindings unchanged.