Epic: Golang backend IR -> Go module/workspace

[DamianReeves]

Tracks delivery of the Morphir Golang backend and pipeline integration.\n\nBeads: morphir-bq3\nRequirements: docs/golang-backend-requirements.md

[DamianReeves]

Epic completed. All subtasks delivered:

• Scaffold golang binding module and package layout
• Implement IR -> Go module/workspace generator (gen step)
• Add golang make/build pipeline steps
• Expose morphir golang CLI commands
• Add tests and example fixtures
• Integrate with make/build/gen toolchain framework (PR feat(golang): implement Go toolchain adapter #529)