v15.4.0-canary.60

Core Changes

• [devtools] Add a query parameter to restart endpoint to invalidate the persistent cache: #79425
• Implement handler interface for app-page: #79568
• Migrate app route to handler interface: #80008
• Turbopack Build: Fix underscore path tests: #79778
• Fix watchmode for taskr tasks: #80020

Misc Changes

• fix: update rspack production build output snapshot: #79766

Credits

Huge thanks to @SyMind, @bgw, @ijjk, @timneutkens, and @eps1lon for helping!