feat: per-turn memory writes with witness flags

chat/services/memory_write.py

@@ -0,0 +1,61 @@
+"""Per-turn memory writes (T21).
+
+After ``assistant_turn`` lands, the turn flow records a ``memory_written``
+event for each present POV owner. Phase 1 single-bot turns only have the
+host bot as a memory-store owner — ``you`` doesn't have a memory store in
+v1 — so we write exactly one row per turn.
+
+Phase 1 simplifications (per plan §11.1, T27 will refine):
+
+- ``pov_summary`` is the assistant's raw narrative text. T27 rewrites at
+  scene close into per-POV summary form.
+- ``significance`` defaults to ``1`` (Notable). T22's async significance
+  pass overwrites via a follow-up event.
+- Witness flags are hard-coded ``[you=1, host=1, guest=0]``. Phase 2 will
+  derive them from ``chat.guest_bot_id`` once a guest can be present.
+"""
+
+from __future__ import annotations
+
+from sqlite3 import Connection
+
+from chat.eventlog.log import append_and_apply
+
+
+def record_turn_memory(
+    conn: Connection,
+    *,
+    chat_id: str,
+    host_bot_id: str,
+    narrative_text: str,
+    scene_id: int | None = None,
+    chat_clock_at: str | None = None,
+    source: str = "direct",
+    significance: int = 1,
+) -> int:
+    """Append a ``memory_written`` event for the host bot's POV of this turn.
+
+    Uses :func:`chat.eventlog.log.append_and_apply` (not raw
+    :func:`append_event`) so the new memory row is projected immediately
+    without re-running prior non-idempotent handlers (e.g. ``edge_update``
+    deltas). Returns the new event id.
+    """
+    payload: dict = {
+        "owner_id": host_bot_id,
+        "chat_id": chat_id,
+        "pov_summary": narrative_text,
+        "witness_you": 1,
+        "witness_host": 1,
+        "witness_guest": 0,
+        "source": source,
+        "reliability": 1.0,
+        "significance": significance,
+        "pinned": 0,
+        "auto_pinned": 0,
+    }
+    if scene_id is not None:
+        payload["scene_id"] = scene_id
+    if chat_clock_at is not None:
+        payload["chat_clock_at"] = chat_clock_at
+
+    return append_and_apply(conn, kind="memory_written", payload=payload)