Revert "perf: optimize prefix caching by skipping system prompt rebuild on ev…" This reverts commit eafa4144c2577a45b7007a177b701863b98d1dfa.
Revert "perf: optimize prefix caching by skipping system prompt rebuild on ev…" This reverts commit eafa4144c2577a45b7007a177b701863b98d1dfa.