Rehearse API Contract Migrations in Daytona

[thefinalmilkman]

Writer's Checklist

Writing Structure

• Uses a distinct API contract migration rehearsal rather than duplicating existing bounty workflows.
• Includes an introduction, TL;DR, step-by-step setup, confirmation steps, and troubleshooting.
• Includes a visual workflow diagram, comparison tables, prompts, and commands.
• Uses current Daytona sandbox CLI commands and does not claim that the current CLI automatically interprets devcontainer.json.

Companion Contributions

• Omni Engineer Dev Container PR: Add Daytona devcontainer Doriandarko/omni-engineer#44
• Claude Engineer Dev Container PR: Add Daytona devcontainer Doriandarko/claude-engineer#269
• Public starter project with passing tests: https://github.com/thefinalmilkman/daytona-api-contract-migration-demo

Asset Management and Definitions

• Adds an original SVG workflow diagram under guides/assets.
• Adds an API contract migration definition.
• Adds a first-time author profile.

Validation

• npx markdownlint guides/20260603_guide_rehearse_api_contract_migrations_in_daytona.md definitions/20260603_definition_api_contract_migration.md authors/thefinalmilkman.md
• git diff --check
• SVG parsed as XML and rendered for visual inspection.
• Demo project: 3 passed with pytest -q.
• Companion Dev Container JSON files parse successfully.
• Omni Engineer: python -m compileall main.py.
• Claude Engineer: python -m compileall app.py ce3.py config.py tools prompts.

Closes #36
/claim #36