Coding Agents: Moving From "Bash Mimics" to "AST Manipulators"

We replaced brittle text-based file editing with Elixir execution to improve coding agents. This allows for zero context re-reads, localized logic, native multitasking, and dynamic introspection. We unlocked these advantages by giving the model full Elixir execution to edit files directly, rather than relying on custom edit primitives or specialized editing tools.