feat: per-event reminders + default reminder setting (server)

local_events gains a `reminders` TEXT column (comma-separated minutes-before-
start, like exdate); EventCreate/EventUpdate accept a `reminders: [int]` list
and build_local_event_dict emits it back as a list. user_settings gains
`default_reminder_minutes` (nullable int, null = off), exposed/updatable via
/api/settings (explicit null persists as off). Migrations added in _migrate().
Clients (iOS/Android) schedule the OS notifications locally from these.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/local_events_util.py

@@ -128,6 +128,7 @@ def build_local_event_dict(
         "type": "local",
         "creator": creator,
         "private": bool(ev.is_private),
+        "reminders": [int(x) for x in (ev.reminders or "").split(",") if x.strip().lstrip("-").isdigit()],
     }
     if owner is not None:
         d["owner"] = owner

backend/main.py

@@ -102,6 +102,20 @@ def _migrate():
         except Exception:
             pass
 
+        try:
+            conn.execute(text("ALTER TABLE local_events ADD COLUMN reminders TEXT"))
+            conn.commit()
+            logging.info("Migration: added reminders to local_events")
+        except Exception:
+            pass
+
+        try:
+            conn.execute(text("ALTER TABLE user_settings ADD COLUMN default_reminder_minutes INTEGER"))
+            conn.commit()
+            logging.info("Migration: added default_reminder_minutes to user_settings")
+        except Exception:
+            pass
+
         try:
             conn.execute(text("ALTER TABLE user_settings ADD COLUMN month_divider_color VARCHAR(7) DEFAULT '#7090c0'"))
             conn.commit()

backend/models.py

@@ -101,6 +101,9 @@ class UserSettings(Base):
     # The single local calendar this user shares into all their groups
     # (combined view shows only this calendar per member). NULL = share nothing.
     group_visible_calendar_id = Column(Integer, nullable=True)
+    # Default reminder in minutes-before-start applied to all events client-side
+    # (0 = at start time). NULL = no default reminder.
+    default_reminder_minutes = Column(Integer, nullable=True)
 
     user = relationship("User", back_populates="settings")
 
@@ -133,6 +136,8 @@ class LocalEvent(Base):
     color = Column(String(7), nullable=True)
     rrule = Column(Text, nullable=True)
     exdate = Column(Text, nullable=True)  # Comma-separated YYYYMMDD dates to exclude
+    # Comma-separated minutes-before-start for reminders, e.g. "10,60" (0 = at start).
+    reminders = Column(Text, nullable=True)
     # Creator: set server-side from the auth token on create, never from the client.
     creator_id = Column(Integer, ForeignKey("users.id"), nullable=True)
     # For imported events without a local user (from the .ics ORGANIZER field).

backend/routers/local_router.py

@@ -1,6 +1,6 @@
 import uuid
 from datetime import datetime, timezone
-from typing import Optional
+from typing import List, Optional
 
 from fastapi import APIRouter, Depends, Form, HTTPException, Query, UploadFile, File
 from fastapi.responses import Response
@@ -43,6 +43,7 @@ class EventCreate(BaseModel):
     color: Optional[str] = None
     rrule: Optional[str] = None
     private: bool = False
+    reminders: Optional[List[int]] = None  # minutes before start (0 = at start)
 
 
 class EventUpdate(BaseModel):
@@ -56,6 +57,7 @@ class EventUpdate(BaseModel):
     rrule: Optional[str] = None
     exdate: Optional[str] = None
     private: Optional[bool] = None
+    reminders: Optional[List[int]] = None
 
 
 class ShareCreate(BaseModel):
@@ -247,6 +249,7 @@ def create_event(
         color=data.color,
         rrule=data.rrule,
         is_private=data.private,
+        reminders=(",".join(str(m) for m in data.reminders) if data.reminders else None),
         creator_id=current_user.id,  # server-side, never from the client
     )
     db.add(ev)
@@ -296,6 +299,8 @@ def update_event(
         if data.exdate not in dates:
             dates.append(data.exdate)
         ev.exdate = ",".join(dates)
+    if data.reminders is not None:
+        ev.reminders = ",".join(str(m) for m in data.reminders) if data.reminders else None
     db.commit()
     return {"ok": True}
 

backend/routers/settings_router.py

@@ -29,6 +29,7 @@ class SettingsUpdate(BaseModel):
     bg_color:   Optional[str] = None
     private_event_visibility: Optional[str] = None
     group_visible_calendar_id: Optional[int] = None
+    default_reminder_minutes: Optional[int] = None  # null = off
 
 
 def _settings_dict(s: models.UserSettings) -> dict:
@@ -50,6 +51,7 @@ def _settings_dict(s: models.UserSettings) -> dict:
         "bg_color":   s.bg_color,
         "private_event_visibility": s.private_event_visibility or "busy",
         "group_visible_calendar_id": s.group_visible_calendar_id,
+        "default_reminder_minutes": s.default_reminder_minutes,
     }
 
 
@@ -92,7 +94,7 @@ def update_settings(
     # For these three override colours, an explicit null is meaningful
     # ("reset to default") and must be persisted as NULL. All other fields
     # keep the previous behaviour where a null/missing value is ignored.
-    NULLABLE_OVERRIDES = {"text_color", "line_color", "bg_color", "group_visible_calendar_id"}
+    NULLABLE_OVERRIDES = {"text_color", "line_color", "bg_color", "group_visible_calendar_id", "default_reminder_minutes"}
     update_data = data.model_dump(exclude_unset=True)
     for field, value in update_data.items():
         if field in NULLABLE_OVERRIDES: