Prune stale merged branches (SQLAnvil reintegration/rename work)

[ihistand]

Leftover feature/fix branches from the Postgres reintegration + Dataform→SQLAnvil rename are all merged into main and can be deleted.

Local branches to delete (9, all merged into main)

• adapter/postgres-deps
• adapter/postgres-proto-additions
• adapter/postgres-relocate
• adapter/postgres-skeleton
• adapter/postgres-sql-generator (local-only)
• fix/node-toolchain-pin
• fix/rules-docker-decl
• rename/dataform-to-sqlanvil
• restore-postgres-adapter

origin copies to delete (8, merged into origin/main)

Same list minus adapter/postgres-sql-generator (absent on origin).

Keep

• dataform — upstream reference snapshot (tip: "Bump DF_VERSION … #2194"), not a stale feature branch.
• Unmerged branches (ci/bq-test-creds-env, docs/branch-strategy, docs/npm-publishing, docs/site-plan) — leave for now; they may hold unfinished work.

Out of scope (separate, larger cleanup)

origin carries dozens of inherited upstream branches from dataform-co/dataform (add-assertion-option, bq-cost, bump_bigquery_*, …). Pruning those is a bigger decision — track separately.

[ihistand]

Investigation: it's an 11-PR stacked chain, not just loose branches

All these branches back open, stacked PRs (each based on the previous, not on main):

PR	head → base	status
#1–#7	rename → … → adapter/postgres-skeleton (stacked)	landed on main (branches are ancestors of main) — obsolete
#11	docs/npm-publishing → restore-postgres-adapter	content migrated to SQLAnvil/docs (npm_publishing.md) — obsolete
#9	ci/bq-test-creds-env → adapter/postgres-skeleton	code (index_test_base.ts env handling) landed on main; also adds docs/gcp_test_project_setup.md (not migrated)
#8	docs/site-plan → restore-postgres-adapter	adds docs/docs_site_plan.md (not migrated)
#10	docs/branch-strategy → restore-postgres-adapter	adds docs/branch_strategy.md (not migrated)

Because they're stacked, deleting branches piecemeal cascades (a deleted base auto-retargets/closes its child PR). So the clean path is to close all 11 PRs as superseded (work landed on main / docs moved to the SQLAnvil/docs repo) and delete all the branches except dataform.

One decision blocks it: 3 doc drafts live only in these branches and were never migrated — docs/gcp_test_project_setup.md, docs/docs_site_plan.md, docs/branch_strategy.md. Need to migrate (the useful ones) or discard before deleting.

(Local copies of the 7 merged branches were already deleted — harmless; they still exist on origin.)

[ihistand]

Done.

• Closed all 11 stacked PRs (refactor: rename dataform → sqlanvil #1–docs: npm publishing runbook + placeholder record #11) as superseded (work landed on main / docs moved to SQLAnvil/docs).
• Deleted 12 origin branches + the local branches. Kept dataform (upstream reference snapshot).
• Migrated the one un-migrated draft, gcp_test_project_setup.md, to SQLAnvil/docs (with corrected SA_TEST_BIGQUERY_PROJECT env-var names); discarded the obsolete branch_strategy.md and docs_site_plan.md planning drafts (recoverable from the closed PRs if ever needed).

Out of scope / follow-up: origin still carries dozens of inherited upstream branches from dataform-co/dataform (add-assertion-option, bq-cost, bump_bigquery_*, …) — a separate, larger cleanup worth its own issue.