chore: add changeset for changed keys feature

Author: piotrski

.changeset/surface-changed-keys.md

@@ -0,0 +1,7 @@
+---
+"agent-react-devtools": minor
+---
+
+feat: surface specific changed prop/state/hook keys in profiling output
+
+Add `ChangedKeys` interface carrying the specific changed keys (props, state, hooks) alongside cause type strings in `ComponentRenderReport` and `CommitDetail`. This makes profiling output more actionable — agents now see *which* props/state/hooks changed, not just *that* they changed. Keys are deduplicated across commits and displayed in all profiling formatters.