Amazon just drew a line in the sand. No more Fire TV Sticks that let users install apps from anywhere but its own store. The change hit with the Fire TV Stick HD, announced April 15, 2026, and it’s locked in for all future models. Product pages now flash a stark warning: “For enhanced security, this device prevents sideloading or installing apps from unknown sources. Only apps from the Amazon Appstore are available for download.” This isn’t subtle. Vega OS powers the shift—a Linux-based system Amazon rolled out first on Echo Show 5 in November 2023, then Echo Hub in April 2024. By October 2025, the Fire TV Stick 4K Select ditched Android’s Fire OS for Vega. Now the HD model follows, confirming what developers spotted on Amazon’s site back in January 2026: apps must already sit in the Appstore to run. Sideloading? Reserved for registered developer devices only. Why now? Piracy.…