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/admin/service.py

@@ -0,0 +1,51 @@
+from fastapi import HTTPException, status
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.modules.admin.schemas import BusinessSummary, PlatformStats
+from app.modules.business.models import Business
+from app.modules.reservations.models import Reservation
+
+VALID_STATUSES = {"trial", "active", "suspended"}
+
+
+async def list_businesses(db: AsyncSession) -> list[Business]:
+    result = await db.execute(select(Business).order_by(Business.created_at.desc()))
+    return result.scalars().all()
+
+
+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_status(db: AsyncSession, business_id: int, new_status: str) -> Business:
+    if new_status not in VALID_STATUSES:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Estado inválido. Opciones: {', '.join(VALID_STATUSES)}",
+        )
+    business = await get_business(db, business_id)
+    business.status = new_status
+    await db.commit()
+    await db.refresh(business)
+    return business
+
+
+async def get_platform_stats(db: AsyncSession) -> PlatformStats:
+    total = (await db.execute(select(func.count(Business.id)))).scalar_one()
+    active = (
+        await db.execute(
+            select(func.count(Business.id)).where(Business.status == "active")
+        )
+    ).scalar_one()
+    reservations = (await db.execute(select(func.count(Reservation.id)))).scalar_one()
+
+    return PlatformStats(
+        total_businesses=total,
+        active_businesses=active,
+        total_reservations=reservations,
+    )