fix(claude_sdk,conversations,rotation): context size from the last api call, new-day text by rotation reason

src/beaver_gateway/core/conversations.py

@@ -23,7 +23,7 @@ import logging
 import re
 import uuid
 from dataclasses import dataclass, field
-from datetime import UTC, datetime, timedelta
+from datetime import UTC, date, datetime, timedelta
 from typing import TYPE_CHECKING, Any, cast
 
 from claude_agent_sdk import (
@@ -134,6 +134,19 @@ class SeedContext:
     title: str | None
 
 
+@dataclass(frozen=True, slots=True)
+class NewDayContext:
+    """What the new master hears first.
+
+    ``reason`` is ``ночь`` / ``возраст`` / ``транскрипт`` - only the first
+    one is actually a new day.
+    """
+
+    day: date
+    reason: str
+    moved: int
+
+
 @dataclass(frozen=True, slots=True)
 class ConversationTexts:
     """Texts the gateway cannot invent for a setup.
@@ -155,7 +168,10 @@ class ConversationTexts:
         "Этот мастер закрывается ({reason}). Напиши хендаут за {day}: справку "
         "на утро, не задание - прошедшее время, без повелительного наклонения."
     )
-    new_day: str = "Новый день: мастер сменился, хендаут за {day} записан."
+    new_day: Callable[[NewDayContext], Awaitable[str] | str] | str = (
+        "Мастер сменился ({reason}), хендаут за {day} записан."
+    )
+    """First inject of the new master; a callable sees the rotation reason."""
     distill: Callable[[DistillContext], Awaitable[str] | str] | None = None
     """The distiller fork's first message (§8.4): which chat, what day, where
     the digest goes; ``None`` uses a path-less default."""
@@ -553,9 +569,7 @@ class Conversations:
                     .limit(1)
                 )
             ).first()
-        if row is None:
-            return 0
-        return row.input_tokens + row.cache_read_tokens + row.cache_creation_tokens
+        return context_of(row)
 
     async def usage_tokens(self, since: datetime) -> int:
         async with self._db.session() as session:
@@ -1213,9 +1227,18 @@ class Conversations:
                     _log.exception("%s could not mark %s", fe.name, conv.external_id)
         return marked
 
-    async def new_day(self, conv: Conversation, *, moved: int = 0) -> InjectQueueItem:
-        day = datetime.now(UTC).astimezone().date().isoformat()
-        text = self._texts.new_day.format(day=day)
+    async def new_day(
+        self, conv: Conversation, *, reason: str = "ночь", moved: int = 0
+    ) -> InjectQueueItem:
+        ctx = NewDayContext(
+            day=datetime.now(UTC).astimezone().date(), reason=reason, moved=moved
+        )
+        source = self._texts.new_day
+        if isinstance(source, str):
+            text = source.format(day=ctx.day.isoformat(), reason=ctx.reason)
+        else:
+            produced: Any = source(ctx)
+            text = await produced if inspect.isawaitable(produced) else produced
         if moved:
             text += f" Инжектов переехало из старого мастера: {moved}."
         return await self.inject(
@@ -1902,3 +1925,17 @@ def _usage_dict(capture: TurnCapture) -> dict[str, Any] | None:
         "cost_usd": usage.cost_usd,
         "duration_ms": usage.duration_ms,
     }
+
+
+def context_of(row: Usage | None) -> int:
+    """Context size of a turn.
+
+    The last API call's input, or, for rows written before it was recorded,
+    the per-call average of the turn's input sums.
+    """
+    if row is None:
+        return 0
+    if row.context_tokens:
+        return row.context_tokens
+    total = row.input_tokens + row.cache_read_tokens + row.cache_creation_tokens
+    return round(total / max(row.num_turns or 1, 1))