Rebase workflow for branches with Alembic migrations + generated SDK files

When rebasing a feature branch that adds both Alembic migrations and auto-generated SDK files (OpenAPI client, lockfiles) onto a master that has also advanced:

1. Generated file conflicts: During rebase, take either side (git checkout --theirs) for generated files like openapi.json and SDK .ts files. Don't try to merge them — the content is throwaway.
2. Regenerate after rebase: Run the generation command once after rebase completes (e.g. ff build openapi-sdk). This picks up types/routes from both master and the feature branch.
3. Alembic heads: If both sides added migrations, check for duplicate down_revision values. The newer migration's down_revision must chain after the other.
4. Cherry-pick skips: Git may skip commits that were already cherry-picked to master. The --reapply-cherry-picks flag forces them, but usually skipping is correct.
5. Amend + prettier: If the regenerated SDK needs formatting, git commit --amend will fail on the first try (prettier modifies files). Immediately retry — the formatted files are already staged.

Key insight: resolve generated-file conflicts quickly during rebase (don't try to merge them), then regenerate everything in one pass. The generation tool is the source of truth, not the conflict resolution.