[cultron]

Into feat/migration-plan, not main. Fixes #148.

What changes

• apso migrate and apso migrate generate now write the planned migration in the service's own format. TypeScript gets a TypeORM class (as before). Python gets an Alembic revision in alembic/versions/, with down_revision chained to the current head. Go gets a goose SQL file in migrations/. The plan JSON is still saved beside it. latestPlannedMigration and migrationsDir know each language's folder and file extension.
• Python and Go files are named YYYYMMDDHHMMSS_<snake_name>, the same as goose's own files, so goose sorts them in the right order.
• Verify for Python and Go does not use TypeORM:
  1. Apso's DDL writer builds the deployed schema in PGlite.
  2. The seed rows load, and the migration's SQL runs exactly as written in the file.
  3. The data-loss and --check steps run as they do for TypeScript.
  4. Drift is checked with catalogDiff against a fresh PGlite build of the new .apsorc.
  5. down() runs, and a second catalog diff must match the deployed schema. This step is skipped when down() is irreversible.
• TypeScript verify is unchanged.
• migrateUnsupported is removed. --typeorm still requires a TypeScript service.
• apso migrate: generated Python (Alembic) migrations do not compile #148: SQL now goes into Python as a JSON string literal, which is also a valid Python string literal, instead of """...""". This applies to the new Alembic writer and to the old PythonGenerator.generateMigration. On the Go side, goose output wraps any statement that contains its own ; in StatementBegin/StatementEnd. The old Go generator gets the same wrapping.

Tests

• test/lib/ddl/wrappers.test.ts:
  • Alembic and goose snapshots for all 8 plan fixtures.
  • python3 -m py_compile on every Alembic file. If python3 is missing, the test falls back to checking that each SQL literal round-trips.
  • The SQL read back from each file must equal the rendered SQL.
  • Regression test for apso migrate: generated Python (Alembic) migrations do not compile #148.
  • Tests for irreversible down, goose statement wrapping, and Alembic head detection.
  • verify runs end to end for python and go on rename-field, split-field and extract-entity, using each fixture's seed.sql and checks.sql, and must pass every step. split-field passes --accept-loss contact.fullName.
  • A drift test: removing the rename from the file must make verify fail.
• The answers map and answeredPlan helper move from change.test.ts to test/lib/ddl/answers.ts so both test files can use them.
• Full suite: 486 passed, 19 skipped (the opt-in suite). npm run lint: 0 errors.
• Manual check: two chained Python revisions written by writePlannedMigration load in real Alembic 1.16.4. alembic history shows the chain, and alembic upgrade head --sql prints the expected SQL.

Not verified

• goose itself was not run because it is not installed here. The Up/Down parsing used by verify is checked, but the goose CLI never parsed the files.
• Neither wrapper was run against a real Postgres server. All database checks ran on PGlite.
• The old PythonGenerator.generateMigration (migrate sandbox) still writes down_revision = None, so a second sandbox migration creates a second Alembic head. I did not change this.