6da625d509
Replace per-scenario Alembic migration runs (~0.5-3s × 25 migrations) with a pre-migrated template SQLite database copied in ~1ms: - New scripts/create_template_db.py creates a fully-migrated SQLite file using Base.metadata.create_all() + alembic stamp (34 tables, ~5ms). - noxfile.py unit_tests and coverage_report sessions generate the template before test execution, propagating CLEVERAGENTS_TEMPLATE_DB env var to all behave-parallel workers. - features/environment.py before_all() installs a monkey-patch on MigrationRunner.init_or_upgrade that copies the template for fresh scenario temp DBs (cleveragents_* / cleveragents_test_* prefix), falling through to real migrations for :memory:, existing files, non-SQLite, and custom URLs used by migration-runner unit tests. Quick wins: - cli_streaming_steps.py: sleep(0.5) → sleep(0.05) in wait-for-completion - cli_streaming.feature: remove redundant Background re-declaration in scenario 7 (already inherited from Feature-level Background) Part of #478. Closes #483.