Reset current instance

Editor assessment

Tight and effective. `fix(ssr)` scopes the change to server-side rendering, 'reset current instance' is a short imperative subject that fits any length constraint, and the footer `fix #6110` links the originating report while `(#6184)` records the contributing PR — exactly the pairing you want for traceability. The one weakness is the absence of explanatory body text: 'reset current instance' is meaningful to core developers but opaque to others, and a sentence describing the failure mode (state leaking across requests, presumably) would make the changelog entry and future debugging easier. As it stands, the message conforms to the spec in every structural respect and will automate cleanly as a patch. A model of brevity, marginally under-documented.