fix(stages): нормализовать aware-даты этапов к поясу оргединицы

asyncpg не принимает aware-datetime для CAST AS TIMESTAMP WITHOUT TIME ZONE (400).
Даты переводятся в пояс оргединицы и становятся naive, SQL приписывает тот же offset.
timezone_from_offset вынесен в src/core/timezones.py, добавлен to_org_local_naive.
Aware-дата при NULL utc_offset оргединицы даёт 422.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/src/api/v1/form_phases.py

@@ -25,22 +25,11 @@ from src.api.v1.deps import (
     require_admin,
 )
 from src.db.session import get_db
+from src.core.timezones import timezone_from_offset
 
 router = APIRouter(prefix="/stages", tags=["stages"])
 
 
-def timezone_from_offset(offset: str) -> datetime.timezone | None:
-    if not offset:
-        return None
-    
-    hours = int(offset[1:])
-    return datetime.timezone(
-        datetime.timedelta(
-            hours=hours if offset[0] == '+' else -hours
-        )
-    )
-
-
 @router.get("/form/{form_id}")
 async def get_form_phases(
     form_id: int,
@@ -100,6 +89,7 @@ async def create_form_phase(
         budget_form=form, 
         body=body, 
         user=current_user,
+        utc_offset=org_unit.utc_offset,
     )
 
     result = FormPhaseResponse.model_validate(phase)
@@ -128,6 +118,9 @@ async def update_form_phase(
     if not form:
         raise HTTPException(404, "Форма не найдена")
     
+    org_unit_service = OrgUnitService(db)
+    org_unit = await org_unit_service.get(user=current_user, org_unit_id=form.org_unit_id)
+
     fp_service = FormPhaseService(db)
     phase = await fp_service.update(
         budget_form=form,
@@ -136,13 +129,12 @@ async def update_form_phase(
         phase_code=phase_code,
         body=body,
         user=current_user,
+        utc_offset=org_unit.utc_offset,
     )
     
     if not phase:
         raise HTTPException(404, "Этап не найден")
 
-    org_unit_service = OrgUnitService(db)
-    org_unit = await org_unit_service.get(user=current_user, org_unit_id=form.org_unit_id)
     result = FormPhaseResponse.model_validate(phase)
 
     if org_unit.utc_offset:
@@ -255,6 +247,7 @@ async def create_form3_phase(
         report_id=report.id, 
         body=body, 
         user=current_user,
+        utc_offset=org_unit.utc_offset,
     )
 
     result = Form3PhaseResponse.model_validate(phase)
@@ -293,19 +286,21 @@ async def update_form3_phase(
     if not report:
         raise HTTPException(404, "Форма не найдена")
     
+    org_unit_service = OrgUnitService(db)
+    org_unit = await org_unit_service.get(user=current_user, org_unit_id=report.project.org_unit_id)
+
     f3p_service = Form3PhaseService(db)
     phase = await f3p_service.update(
         report_id=report.id,
         phase_code=phase_code,
         body=body,
         user=current_user,
+        utc_offset=org_unit.utc_offset,
     )
     
     if not phase:
         raise HTTPException(404, "Этап не найден")
 
-    org_unit_service = OrgUnitService(db)
-    org_unit = await org_unit_service.get(user=current_user, org_unit_id=report.project.org_unit_id)
     result = Form3PhaseResponse.model_validate(phase)
 
     if org_unit.utc_offset:

api/src/core/timezones.py

@@ -0,0 +1,40 @@
+import datetime
+
+from fastapi import HTTPException
+
+
+def timezone_from_offset(offset: str) -> datetime.timezone | None:
+    """Строка вида '+03' / '-05' (org_unit.utc_offset) -> datetime.timezone."""
+    if not offset:
+        return None
+
+    hours = int(offset[1:])
+    return datetime.timezone(
+        datetime.timedelta(
+            hours=hours if offset[0] == '+' else -hours
+        )
+    )
+
+
+def to_org_local_naive(
+    dt: datetime.datetime, utc_offset: str | None
+) -> datetime.datetime:
+    """Приводит дату к местному naive-времени оргединицы.
+
+    Naive-значение возвращается без изменений (оно уже местное). Aware-значение
+    переводится в пояс оргединицы, после чего tzinfo отбрасывается: SQL-функции
+    (v3.add_form_phase и др.) затем приписывают тот же offset, и момент времени
+    сохраняется. Если у оргединицы нет utc_offset, а дата aware - 422.
+    """
+    if dt.tzinfo is None:
+        return dt
+    tz = timezone_from_offset(utc_offset) if utc_offset else None
+    if tz is None:
+        raise HTTPException(
+            status_code=422,
+            detail=(
+                "Дата передана с часовым поясом, но у оргединицы формы не "
+                "задан utc_offset. Передайте дату без часового пояса."
+            ),
+        )
+    return dt.astimezone(tz).replace(tzinfo=None)

api/src/services/form3_phase_service.py

@@ -3,6 +3,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from src.db.models.form3_phase import Form3Phase
 from src.db.models.form_type import FormType, FormTypeEnum
 from src.repository.form3_phase_repository import Form3PhaseRepository
+from src.core.timezones import to_org_local_naive
 from src.core.errors import AccessDeniedException, ValidationsError
 from src.db.models.role import UserRoleEnum
 from src.db.models.app_user import AppUser
@@ -55,6 +56,7 @@ class Form3PhaseService:
             report_id: int,
             body: Form3PhaseCreate, 
             user: AppUser,
+            utc_offset: str | None = None,
     ) -> Form3Phase:
         if user.role_id != UserRoleEnum.ADMIN:
             raise AccessDeniedException
@@ -62,13 +64,15 @@ class Form3PhaseService:
         self._validate_form3_phase(
             form_phase=body,
         )
+        opens_at = to_org_local_naive(body.opens_at, utc_offset)
+        closes_at = to_org_local_naive(body.closes_at, utc_offset)
         return await self.f3p_repo.create(
             report_id=report_id,
             phase_code=body.phase_code,
             role=body.role,
             column_keys=body.column_keys,
-            opens_at=body.opens_at,
+            opens_at=opens_at,
-            closes_at=body.closes_at,
+            closes_at=closes_at,
         )
 
     async def update(
@@ -77,6 +81,7 @@ class Form3PhaseService:
             phase_code: str,
             body: Form3PhaseUpdate,
             user: AppUser,
+            utc_offset: str | None = None,
     ) -> Form3Phase:
         if user.role_id != UserRoleEnum.ADMIN:
             raise AccessDeniedException
@@ -86,6 +91,9 @@ class Form3PhaseService:
         )
 
         data = body.model_dump(exclude_unset=True)
+        for key in ("opens_at", "closes_at"):
+            if data.get(key) is not None:
+                data[key] = to_org_local_naive(data[key], utc_offset)
         if not data:
             return await self.f3p_repo.get(
                 report_id=report_id,

api/src/services/form_phase_service.py

@@ -1,5 +1,6 @@
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from src.core.timezones import to_org_local_naive
 from src.core.errors import AccessDeniedException, ValidationsError
 from src.db.models.budget_form import BudgetForm
 from src.db.models.role import UserRoleEnum
@@ -74,6 +75,7 @@ class FormPhaseService:
             user: AppUser,
             budget_form_id: int | None = None,
             budget_form: BudgetForm | None = None,
+            utc_offset: str | None = None,
     ) -> FormPhase:
         assert budget_form or budget_form_id
         if user.role_id != UserRoleEnum.ADMIN:
@@ -88,6 +90,8 @@ class FormPhaseService:
             form_phase=body,
             budget_form=budget_form,
         )
+        opens_at = to_org_local_naive(body.opens_at, utc_offset)
+        closes_at = to_org_local_naive(body.closes_at, utc_offset)
         return await self.fp_repo.create(
             budget_form_id=budget_form_id or budget_form.id,
             sheet=body.sheet,
@@ -95,8 +99,8 @@ class FormPhaseService:
             phase_code=body.phase_code,
             role=body.role,
             column_keys=body.column_keys,
-            opens_at=body.opens_at,
+            opens_at=opens_at,
-            closes_at=body.closes_at,
+            closes_at=closes_at,
         )
 
     async def update(
@@ -108,6 +112,7 @@ class FormPhaseService:
             user: AppUser,
             budget_form_id: int | None = None,
             budget_form: BudgetForm | None = None,
+            utc_offset: str | None = None,
     ) -> FormPhase:
         assert budget_form or budget_form_id
         if user.role_id != UserRoleEnum.ADMIN:
@@ -126,6 +131,9 @@ class FormPhaseService:
         )
 
         data = body.model_dump(exclude_unset=True)
+        for key in ("opens_at", "closes_at"):
+            if data.get(key) is not None:
+                data[key] = to_org_local_naive(data[key], utc_offset)
         if not data:
             return await self.fp_repo.get(
                 budget_form_id=budget_form_id or budget_form.id,