feat(persistence): PostgreSQL assistant store, chat persist fixes, gateway scripts

- Add SQLAlchemy Core repos, pg adapter/compat, assistant_store factory, Alembic bootstrap and migration/cutover scripts.

- Harden chat_message writes (NUL scrub for PG), turn_uuid on attempt failure, WS turn_runner fallbacks and gateway executed_turn_uuid init.

- start_gateway: log paths, PS7 stderr handling via cmd, background stdout/stderr redirect; runtime assistant_runtime_log_dir export.

- Ops: clear_all_chat_sessions with PG-only --postgresql and env-gated wipe; clear_postgres_chat_sessions.ps1.

- Tests: SA repos, pg compat, persist fallback, smoke env isolation; CI and docs touch-ups.

Co-authored-by: Cursor <cursoragent@cursor.com>

svc/persistence/sa_repos/trace_events.py

@@ -0,0 +1,108 @@
+"""trace_event insert + list queries via SQLAlchemy Core."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from sqlalchemy import insert, select
+from sqlalchemy.engine import Engine
+
+from svc.persistence.db.tables import trace_event
+
+
+class TraceEventsSaRepository:
+    __slots__ = ("_engine",)
+
+    def __init__(self, engine: Engine) -> None:
+        self._engine = engine
+
+    def insert_one(
+        self,
+        *,
+        session_id: str,
+        trace_id: str,
+        span_id: str,
+        parent_span_id: str | None,
+        event_type: str,
+        payload: str,
+        timestamp: str,
+    ) -> None:
+        with self._engine.begin() as conn:
+            conn.execute(
+                insert(trace_event).values(
+                    session_id=str(session_id),
+                    trace_id=str(trace_id),
+                    span_id=str(span_id),
+                    parent_span_id=parent_span_id,
+                    event_type=str(event_type),
+                    payload=str(payload),
+                    timestamp=str(timestamp),
+                )
+            )
+
+    def insert_many(self, rows: list[dict[str, Any]]) -> None:
+        if not rows:
+            return
+        with self._engine.begin() as conn:
+            conn.execute(insert(trace_event), rows)
+
+    def list_trace_events_desc(self, *, session_id: str, limit: int) -> list[dict[str, Any]]:
+        sid = str(session_id or "").strip()
+        lim = max(1, int(limit))
+        stmt = (
+            select(
+                trace_event.c.trace_id,
+                trace_event.c.span_id,
+                trace_event.c.parent_span_id,
+                trace_event.c.event_type,
+                trace_event.c.payload,
+                trace_event.c.timestamp,
+            )
+            .where(trace_event.c.session_id == sid)
+            .order_by(trace_event.c.id.desc())
+            .limit(lim)
+        )
+        with self._engine.connect() as conn:
+            return [dict(r) for r in conn.execute(stmt).mappings().all()]
+
+    def list_trace_events_for_trace_asc(
+        self, *, session_id: str, trace_id: str, limit: int
+    ) -> list[dict[str, Any]]:
+        sid = str(session_id or "").strip()
+        tid = str(trace_id or "").strip()
+        lim = max(1, int(limit))
+        if not sid or not tid:
+            return []
+        stmt = (
+            select(
+                trace_event.c.trace_id,
+                trace_event.c.span_id,
+                trace_event.c.parent_span_id,
+                trace_event.c.event_type,
+                trace_event.c.payload,
+                trace_event.c.timestamp,
+            )
+            .where(trace_event.c.session_id == sid, trace_event.c.trace_id == tid)
+            .order_by(trace_event.c.id.asc())
+            .limit(lim)
+        )
+        with self._engine.connect() as conn:
+            return [dict(r) for r in conn.execute(stmt).mappings().all()]
+
+    def list_event_type_timestamp_for_trace(
+        self, *, session_id: str, trace_id: str
+    ) -> list[dict[str, Any]]:
+        sid = str(session_id or "").strip()
+        tid = str(trace_id or "").strip()
+        if not sid or not tid:
+            return []
+        stmt = (
+            select(trace_event.c.event_type, trace_event.c.timestamp)
+            .where(trace_event.c.session_id == sid, trace_event.c.trace_id == tid)
+            .order_by(trace_event.c.id.asc())
+        )
+        with self._engine.connect() as conn:
+            return [dict(r) for r in conn.execute(stmt).mappings().all()]
+
+
+__all__ = ["TraceEventsSaRepository"]