feat: initial commit — HermesMessages SaaS platform

Backend (FastAPI + Python 3.12):
- Multi-tenant auth with JWT: login, register, refresh, Meta OAuth
- Business & BusinessConfig management
- WhatsApp webhook with HMAC signature verification
- Bot engine powered by Claude AI
- Calendar availability with Redis caching
- Reservations CRUD with status management
- Dashboard analytics (stats, agenda, peak hours)
- Billing & plan management
- Admin panel with platform-wide stats
- Async bcrypt via asyncio.to_thread
- IntegrityError handling for concurrent registration race conditions

Frontend (React 18 + Vite + Tailwind CSS):
- Multi-step guided registration form with helper text on every field
- Login page with show/hide password toggle
- Protected routes with AuthContext
- Dashboard with stats cards, bar chart, and daily agenda
- Reservations list with search, filters, and inline status actions
- Calendar with weekly view, slot availability, and date blocking
- Config page: business info, schedules, bot personality
- Billing page with plan comparison and usage bar

Design system:
- Bricolage Grotesque + DM Sans typography
- Emerald primary palette with semantic color tokens
- scale(0.97) button press feedback, ease-out animations
- Skeleton loaders, stagger animations, prefers-reduced-motion support
- Accessible: aria-labels, visible focus rings, 4.5:1 contrast

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/modules/calendar/router.py

@@ -0,0 +1,57 @@
+from datetime import date
+
+import redis.asyncio as aioredis
+from fastapi import APIRouter, Depends, Response
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.core.dependencies import get_current_business
+from app.core.redis import get_redis
+from app.modules.calendar import schemas, service
+
+router = APIRouter()
+
+
+@router.get("/availability", response_model=schemas.DayAvailability)
+async def get_availability(
+    date: date,
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+    redis: aioredis.Redis = Depends(get_redis),
+):
+    return await service.get_available_slots(db, redis, business_id, date)
+
+
+@router.get("/availability/range", response_model=list[schemas.DayAvailability])
+async def get_availability_range(
+    start: date,
+    end: date,
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+    redis: aioredis.Redis = Depends(get_redis),
+):
+    return await service.get_availability_range(db, redis, business_id, start, end)
+
+
+@router.post("/blocked-dates", status_code=201)
+async def add_blocked_date(
+    body: schemas.BlockedDateRequest,
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+    redis: aioredis.Redis = Depends(get_redis),
+):
+    await service.add_blocked_date(db, business_id, body.date)
+    await service.invalidate_slots_cache(redis, business_id, body.date)
+    return {"detail": "Fecha bloqueada"}
+
+
+@router.delete("/blocked-dates/{target_date}", status_code=204)
+async def remove_blocked_date(
+    target_date: date,
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+    redis: aioredis.Redis = Depends(get_redis),
+):
+    await service.remove_blocked_date(db, business_id, target_date)
+    await service.invalidate_slots_cache(redis, business_id, target_date)
+    return Response(status_code=204)