Migrate a dbt project to dbt-core 1.12

You upgrade a dbt-core v1 project all the way to 1.12 — not one minor bump. Two different mechanisms apply, and you must not confuse them:

• Up to 1.8 — genuinely breaking changes with no compatibility shim. You replay every version boundary in order from the project's current version, because consistent changelogs exist only per single minor version.

• After 1.8 — every backwards-incompatible change ships gated behind a behavior-change flag in dbt_project.yml flags:. You do not fix those behaviors. Instead, for each such change the project actually exhibits, you pin its gating flag to false so the project keeps its current semantics and parses on 1.12. Several of these flags already default to true in 1.12, so for an affected project leaving the flag unset silently adopts the new behavior — pinning is what makes the migration behavior-preserving.

  Pin only what applies: a flag for a behavior the project does not use is dead config that hides the ones that matter. Detection per issue decides.