"trust" and "responsibility" mean nothing for a fully digital entity who isn't required to feed its family, looking for an eventual new job, and being under pressure for not being fired

Code review, style guides, and a large set of tools like fuzzers that try to check for bad behavior before the code makes it into production. At least that's how it is done where I work and the use of agents to write code has not obviated the need for such a process (in fact we have added agents to that large set of tools and seen improvements in code quality as a result).