Added a changelog entry for #7929

.changesets/fix_tylerb_fed_644.md

@@ -0,0 +1,12 @@
+### Query planning errors with progressive override on interface implementations ([PR #7929](https://github.com/apollographql/router/pull/7929))
+
+The router now correctly generates query plans when using [progressive override](https://www.apollographql.com/docs/graphos/schema-design/federated-schemas/entities/migrate-fields#incremental-migration-with-progressive-override) (`@override` with labels) on types that implement interfaces within the same subgraph. Previously, the Rust query planner would fail to generate plans for these scenarios with the error `"Was not able to find any options for {}: This shouldn't have happened."`, while the JavaScript planner handled them correctly.
+
+This fix resolves planning failures when your schema uses:
+- Interface implementations local to a subgraph
+- Progressive override directives on both the implementing type and its fields
+- Queries that traverse through the overridden interface implementations
+
+The router will now successfully plan and execute queries that previously resulted in query planning errors.
+
+By [@TylerBloom](https://github.com/TylerBloom) in https://github.com/apollographql/router/pull/7929