Feat/schema validators session and scopes 2

.agent/memory-bank/activeContext.md

@@ -1,7 +1,9 @@
 # Active Context
 
 ## Current Work
-- **PRD follow-on:** optional `infer-schema` CLI + Postgres smoke / CI hook; Phase E **U-4** pool-bound `Session` + auto-dirty on `LifeRecord::set`.
+- **lifeguard-derive `validate_fields` + Aggregate (2026-03-31):** `#[validate(custom)]` FailFast vs Aggregate branches in `life_record.rs`; struct-level `#[validation_strategy = "aggregate"|"fail_fast"]` parsed in `attributes.rs`, registered on `LifeModel`/`LifeRecord` derives, emits `ActiveModelBehavior::validation_strategy` when set (so `validate_fields` matches `run_validators` — manual second `impl ActiveModelBehavior` is invalid). Tests `validate_multi_fail_fast` / `validate_multi_aggregate` in `lifeguard-derive/tests/test_minimal.rs`; shared `name_non_empty` in `validate_attr_tests`. Verified: `cargo test -p lifeguard-derive`, `cargo clippy -p lifeguard-derive --all-targets --all-features -- -D warnings`.
+- **README reorg (2026-03-28):** Landing page split — **`ROADMAP.md`**, **`COMPARISON.md`** (repository truth under **`#repository-status`** + competitive matrix + ecosystem + performance). **`STATUS.md`** merged into **`COMPARISON.md`** (2026-03-28). **`README.md`** is pitch + getting started + doc index table. **`ARCHITECTURE.md`** LifeReflector link points to **`VISION.md#the-killer-feature-lifereflector`**. PRD + SEAORM mapping reference **`COMPARISON.md`**.
+- **PRD follow-on:** Phase E **insert-only** session flush for new rows (no PK); `find_related` + scopes per `docs/planning/DESIGN_FIND_RELATED_SCOPES.md`; optional `infer-schema` CLI / CI smoke.
 - **Dev process + Phase D v0 (2026-03-28):** `docs/planning/DEV_RUSTDOC_AND_COVERAGE.md` (rustdoc + coverage checklist); Phase D `ColumnTrait::f_*` for SeaQuery `UPDATE SET`.
 - **PRD Phase C v0 — scopes (2026-03-28):** `SelectQuery::scope`, `IntoScope`, `src/query/scope.rs` docs + tests; PRD §7.7; mapping doc row. Next: Phase D F() or README G6 follow-ups if requested.
 - **PRD Phase B v0 — validators (2026-03-28):** Landed trait-based validation pipeline + `ActiveModelError::Validation`; derive wires `run_validators` after `before_insert`/`before_update`. PRD `docs/planning/PRD_SCHEMA_VALIDATORS_SESSION_AND_SCOPES.md` §6.7 + milestone §0.1. Memory bank updated with this line.
@@ -15,6 +17,12 @@
 - Memory Bank initialized with codegen learnings
 
 ## Recent Changes
+- **Docs — COMPARISON ecosystem + PRD ValidateOp + progress Metrics (2026-03-28):** `COMPARISON.md` — factual **BRRTRouter** / **Lifeguard** / **`may`** vs **Tokio** / **`async`/`await`** / **SeaORM** / **SQLx** / **Diesel (sync)** / **Diesel-async** table; removed absolute “must”/“fundamentally incompatible” wording; performance footnote for Diesel. `PRD_SCHEMA_VALIDATORS_SESSION_AND_SCOPES.md` — `ValidateOp` = `Insert` \| `Update` \| `Delete`; V-1 insert/update/**delete**; §5.7 index scope + §5.7a **index reconciliation** stretch; `.agent/memory-bank/progress.md` **Metrics** block labeled **historical snapshot** with pointers to **Completed**.
+- **`ActiveModelTrait::take` session notify (2026-03-28):** `lifeguard-derive` `life_record.rs` — `__lg_session_notify_dirty()` only when `take` actually changes state (`#field_name.is_some()` or `__update_exprs` contained that column), matching `set`/`set_col` gating. Tests `test_take_noop_when_unset_skips_session_dirty`, `test_take_with_value_or_expr_notifies_session_dirty` in `lifeguard-derive/tests/test_minimal.rs`. `cargo test -p lifeguard-derive`, `cargo clippy -p lifeguard-derive --all-targets --all-features -- -D warnings`.
+- **`SessionIdentityModelCell` / `unsafe impl Send` (2026-03-28):** Cursor review — `Rc` + `unsafe Send` is unsound if the “one thread per `Rc` clone” protocol is violated; acknowledged. Expanded `src/session/identity_model_cell.rs` module docs + `// SAFETY` block: why `ActiveModelTrait: Send` forces `Option<SessionIdentityModelCell>: Send`; that `Arc<RefCell<M>>` does not restore `Send` (`RefCell: !Sync`); pointer to `SECURITY_PROMPT.md` §A.3 and `Arc<Mutex<M>>` as a type-sound long-term direction. No API change in this step.
+- **`migration_db_compare_smoke` CLI assertion (2026-03-28):** `compare_schema_cli_succeeds_when_no_drift` asserted `Tables match` / `Success`, but `MigrationDbCompareReport`’s `Display` prints **`No drift`** when `!has_drift()` (`schema_migration_compare.rs`). Test now asserts `stdout.contains("No drift")`; stderr assert uses named `stderr=` placeholder.
+- **Review nits (2026-03-28):** `tests/db_integration/pool_read_replica.rs` — per-test unique `pool_replica_test_{n}` / `t_pool_replica_smoke_{n}` + `setup_schema_on_primary(executor, schema, table)` to avoid parallel DDL collisions; raw `may_postgres` `query_one` uses a local `String` + `as_str()`. `SessionIdentityModelCell::replace_with` → `try_borrow_mut` + `Result<(), BorrowMutError>`; derive `__lg_session_notify_dirty` documents `to_model()` clone cost + ignores replace error. `DEVELOPMENT.md` — split `lifeguard-migrate` / optional live Postgres files / `db_integration_suite` bullets. `lifeguard-migrate` / tests — named `format!` where applicable; `src/session/uow.rs` left unchanged (already `{e}`/`{rb_err}`; explicit `err = e` trips `clippy::uninlined_format_args`). `predicates::string_utf8_chars_max` already single `chars().count()`. `ModelIdentityMap::register_pending_insert` rustdoc: `PENDING_INSERT_KEY_PREFIX`, `next_pending_id`, wrapping. Verified: `cargo clippy -p lifeguard -p lifeguard-derive -p lifeguard-migrate --all-targets --all-features -- -D warnings`, `cargo test -p lifeguard --lib session::`, `cargo test -p lifeguard-derive`.
+- **ActiveModelTrait `set` / `set_col` vs `__update_exprs` (2026-03-28):** `lifeguard-derive` `life_record.rs` — match arms remove a pending `set_*_expr` only after `Value`→field conversion succeeds, so `InvalidValueType` no longer drops the scheduled F-style expression. Integration tests in `lifeguard-derive/tests/test_minimal.rs` (`test_set_invalid_type_preserves_update_expr`, `test_set_col_invalid_type_preserves_update_expr`, non-PK column). Verified: `cargo test -p lifeguard-derive`; `cargo clippy -p lifeguard -p lifeguard-derive --all-targets --all-features -- -D warnings`.
 - **Toxiproxy fallback test ignored (2026-03-28):** `pooled_read_falls_back_to_primary_when_replica_lagging` is `#[ignore]` (flaky CI: `is_replica_lagging` after proxy disable). Run with `cargo test -- --ignored` when debugging; TODO to stabilize `WalLagMonitor` + re-enable.
 - **Tiltfile — replication test resources (2026-03-28):** Targeted nextest runs for read-replica PRD work (`test-replication-pool`, `test-db-integration-replica`, `test-replication-pool-smoke`) with Kind ports 6543/6544/6545. **`test-replication-pool` / `-smoke`:** added nextest `--status-level pass` so filtered runs do not print one SKIP line per non-matching test in `db_integration_suite` (filter is intentionally narrow; full replica env suite remains `test-db-integration-replica`).
 - **CI Compose + Toxiproxy (2026-03-30):** [Toxiproxy](https://github.com/Shopify/toxiproxy) fronts the streaming replica on host **6547** (API **8474**) so Kind/Tilt can keep **6544** for replica-0. The integration test that PATCHes proxy `enabled` for primary fallback is **`#[ignore]`** until stabilized (see Recent Changes). **Local:** stop Tilt or avoid port collisions — `127.0.0.1:6543` may hit Kind vs Compose primary if both bind.