docs/release-notes: add release notes entry

Author: Roasbeef

docs/release-notes/release-notes-0.7.0.md

@@ -35,11 +35,18 @@
   optimized sending to V2 TAP addresses by removing the need for creating
   tombstone outputs on a full-value send (by using interactive transfers for V2
   addresses).
+
 - [Updated](https://github.com/lightninglabs/taproot-assets/pull/1774) 
   `BuyOrderRequest` and `SellOrderRequest` proto docs to mark `peer_pub_key` as
   required. Previously, the field was incorrectly documented as optional.
   This change corrects the documentation to match the current implementation.
 
+- [Invoice tolerance calculations were fixed to properly account for per-HTLC
+  conversion errors](https://github.com/lightninglabs/taproot-assets/pull/1673).
+  This improves the accuracy of asset payment acceptance by correctly modeling
+  rounding errors that accumulate when converting between asset units and
+  millisatoshis across multiple HTLCs.
+
 # New Features
 
 ## Functional Enhancements