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/business/service.py

@@ -0,0 +1,49 @@
+from fastapi import HTTPException, status
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.modules.business.models import Business, BusinessConfig
+from app.modules.business.schemas import BusinessConfigUpdate, BusinessUpdate
+
+
+async def get_business(db: AsyncSession, business_id: int) -> Business:
+    result = await db.execute(select(Business).where(Business.id == business_id))
+    business = result.scalar_one_or_none()
+    if not business:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Negocio no encontrado")
+    return business
+
+
+async def update_business(
+    db: AsyncSession, business_id: int, data: BusinessUpdate
+) -> Business:
+    business = await get_business(db, business_id)
+    for field, value in data.model_dump(exclude_none=True).items():
+        setattr(business, field, value)
+    await db.commit()
+    await db.refresh(business)
+    return business
+
+
+async def get_business_config(db: AsyncSession, business_id: int) -> BusinessConfig:
+    result = await db.execute(
+        select(BusinessConfig).where(BusinessConfig.business_id == business_id)
+    )
+    config = result.scalar_one_or_none()
+    if not config:
+        config = BusinessConfig(business_id=business_id)
+        db.add(config)
+        await db.commit()
+        await db.refresh(config)
+    return config
+
+
+async def update_business_config(
+    db: AsyncSession, business_id: int, data: BusinessConfigUpdate
+) -> BusinessConfig:
+    config = await get_business_config(db, business_id)
+    for field, value in data.model_dump(exclude_none=True).items():
+        setattr(config, field, value)
+    await db.commit()
+    await db.refresh(config)
+    return config