Frostsnap v0.4.0 fixes two security issues, adds firmware downgrade protection

The absence of reported fund losses is notable, but the two fixes point to edge-case failures in signing integrity and wallet recovery—areas where bugs can silently undermine user trust in self-custody. Adding downgrade protection signals a shift toward hardening the device against physical or supply-chain attacks, which is increasingly relevant as multisig setups become a standard for high-value holdings. The open question is whether these issues stem from isolated code errors or reveal deeper gaps in the signing flow's input validation, and whether other hardware wallets share similar vulnerabilities. Prompt updates remain the only practical mitigation, yet the real test is how Frostsnap communicates these risks to a user base that may assume multisig is bulletproof.