Implement the Trait (`hardware_trait.rs`)

Define the VxHardwarePlugin Rust trait in the compiler tree.

Sub-tasks

• Define the base VxHardwarePlugin trait.
• Implement plugin_name and target_topology methods.
• Implement is_op_supported and annotate_operation for MLIR interception.
• Implement register_passes to allow vendors to inject their MLIR passes.
• Implement lower_to_binary to output the final hardware-specific payload.
• Add preferred_tensor_layout and required_alignment constraints.

Start in the compiler tree with hardware_trait.rs and map the existing MLIR interception and pass-registration entry points before defining the VxHardwarePlugin trait. Review each listed method and constraint, then verify that vendor pass injection, operation support and annotation, lowering to a hardware payload, tensor layout, and alignment are all represented.