Fix fallback heuristic misclassifying dynamic variant as runtime
The dynamicBodyMessage now contains "request-time API" and the
dynamic metadata/viewport messages contain "cookies()", which
caused the fallback string heuristic to classify them as runtime
variant instead of navigation variant.
Fix by matching "A request-time API" only when not preceded by
"Either" (which is unique to the dynamic template), and removing
the cookies() check entirely.
Made-with: Cursor