Defines the behaviour contract for Galixir code generators.
A generator module is responsible for producing the implementation AST that is injected into generated algebra modules during compilation.
Each generator receives a Galixir.Meta structure containing the information
required to generate code for a specific algebra, such as its dimension,
signature, basis blades, and precomputed lookup tables.
Implementations must return a list of quoted expressions (Macro.t()) that can
be inserted into the target module using unquote_splicing/1.
This behaviour allows individual generators to be developed independently while providing a common interface for composing complete algebra implementations.