Add supplements, kettlebell, calendar, push notifications, and PWA support

- Supplement tracking: CRUD endpoints, /today, /logs, Supplements page
- Kettlebell workouts: session tracking, analytics endpoint, ActiveSession page
- Calendar module: events CRUD, calendar components
- Push notifications: VAPID keys, PushSubscription model, APScheduler reminders,
  service worker with push/notificationclick handlers, Profile notifications UI
- PWA: vite-plugin-pwa, manifest, icons, service worker generation
- Frontend: TypeScript types, API modules, ConfirmModal, toast notifications
- Auth fixes: password hashing, nutrition endpoint auth
- CLAUDE.md: project documentation and development guide

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/models/calendar.py

@@ -0,0 +1,27 @@
+import datetime as dt
+from typing import Optional
+
+from sqlmodel import Field, SQLModel
+
+
+class DailyNote(SQLModel, table=True):
+    id: Optional[int] = Field(default=None, primary_key=True)
+    user_id: int = Field(foreign_key="user.id", index=True)
+    date: dt.date = Field(index=True)
+    content: str = Field(default="", max_length=10000)
+    mood: Optional[str] = None  # "great"/"good"/"okay"/"bad"/"awful"
+    energy_level: Optional[int] = None  # 1–10
+    updated_at: dt.datetime = Field(default_factory=dt.datetime.utcnow)
+
+
+class CalendarEvent(SQLModel, table=True):
+    id: Optional[int] = Field(default=None, primary_key=True)
+    user_id: int = Field(foreign_key="user.id", index=True)
+    date: dt.date = Field(index=True)
+    title: str
+    description: Optional[str] = None
+    event_type: str = "general"  # "workout" | "supplement" | "general"
+    color: Optional[str] = None
+    start_time: Optional[str] = None  # "HH:MM"
+    is_completed: bool = False
+    created_at: dt.datetime = Field(default_factory=dt.datetime.utcnow)