Next.js v16.2.0-canary.60: Route cache fixes, React bump, Turbopack polish v16.2.0-canary.60

Canary 60 landed with some solid stability improvements: route cache keying for unprefetched navigations got fixed, React bumped to the latest, and we fixed a bunch of image deployment edge cases (unicode handling included). Turbopack HMR for pages router is working properly now too. Still early canary vibes, but these are the kinds of fixes that make the foundation less wobbly.