The rapid advancement of quantum computing poses a critical long-term threat to current public-key cryptography, with cryptographically relevant quantum computers (CRQCs) potentially capable of breaking widely deployed cryptosystems by running Shor's algorithm, undermining the security of major Internet protocols. This threat has prompted urgent calls for transitioning to post-quantum cryptography (PQC), with NIST finalizing its first set of post-quantum standards in August 2024. However, given the unprecedented scope of the PQC transition, affecting all public-key algorithms, this transition presents significant technical and operational challenges. Migrating complex, widely deployed software ecosystems, such as web browsers and their cryptographic libraries, requires not only algorithm replacement but also architectural flexibility to adapt to evolving standards and implementations.