Model SQL/ORM transaction, commit, and rollback effects

[shaggitza]

Goal

Distinguish staged ORM mutations from durable writes for SQLAlchemy Session/AsyncSession and configured unit-of-work wrappers (#96).

Acceptance criteria

• pending_persistence distinct from durable write
• flush/commit/rollback path evidence
• transaction/context-manager boundaries
• conservative exceptions/control flow
• no promotion when outcome unresolved
• nested transaction, wrapper and real-PR fixtures

[shaggitza]

Progress merged in #131 and #133:

• exact SQLAlchemy stage/flush/begin/commit/rollback contracts
• conservative endpoint-reachable transaction diagnostics
• bounded same-scope lexical stage-to-boundary evidence
• finite Name/Attribute receiver equality and reassignment/control-flow fail-closed gates
• atomic pair caps, immutable provenance, all output formats, and bounded-suite coverage

Persistence remains explicitly not established. General path feasibility, exceptions, context-manager exit, aliases/runtime transaction identity, savepoints, wrappers, removed boundaries, resource coupling, and real-world fixtures remain open.

[shaggitza]

PR #141 merged effect-contract schema-v2 transaction scopes and SQL report schema-v2 scope evidence. SQLAlchemy begin/begin_nested are now exact transaction/savepoint boundaries for sync/async sessions; nearest prior ordered begin preserves scope. All evidence remains diagnostic-only and persistence not established. All 50 bounded tests and Python 3.10–3.12 CI passed. #99 remains open for context-manager exit outcomes, conservative exceptions, configured wrapper summaries, runtime identity, removed boundaries, and real-PR fixtures.

[shaggitza]

PR #142 merged exact sync/async SQL transaction and savepoint context-manager exit evidence. Normal transaction exit makes commit reachable; normal savepoint exit makes release reachable; exceptional exit makes rollback reachable. Outcomes remain conditional and persistence not established. Captured/multiple/dynamic/control-flow cases fail closed. All 50 bounded tests and Python 3.10–3.12 CI passed. Remaining scope: configured wrapper summaries beyond exact contracts, caught/suppressed exception flow, runtime identity, removed boundaries, and adjudicated real-PR fixtures.

[shaggitza]

Ordered flush-evidence tranche merged in PR #301 (6a0719c). Exact SQLAlchemy flush now participates in bounded same-receiver transaction paths while remaining explicitly pending/not durable; deterministic schema-v4 path accounting and text/Markdown/HTML counts are validated. Full Python 3.10–3.12 CI and independent terminal review passed. #99 remains open for general feasibility, exception/alias identity, wrappers, removed boundaries, resource coupling, and real-PR adjudication.