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/billing/router.py

@@ -0,0 +1,33 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.core.dependencies import get_current_business
+from app.modules.billing import schemas, service
+
+router = APIRouter()
+
+
+@router.get("/plan", response_model=schemas.PlanRead)
+async def get_plan(
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+):
+    return await service.get_plan(db, business_id)
+
+
+@router.post("/upgrade", response_model=schemas.PlanRead)
+async def upgrade_plan(
+    body: schemas.UpgradeRequest,
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+):
+    return await service.upgrade_plan(db, business_id, body.plan)
+
+
+@router.get("/usage", response_model=schemas.UsageRead)
+async def get_usage(
+    business_id: int = Depends(get_current_business),
+    db: AsyncSession = Depends(get_db),
+):
+    return await service.get_usage(db, business_id)

backend/app/modules/billing/schemas.py

@@ -0,0 +1,25 @@
+from pydantic import BaseModel
+
+PLAN_LIMITS = {
+    "free": 50,
+    "basic": 500,
+    "pro": -1,  # ilimitado
+}
+
+
+class PlanRead(BaseModel):
+    plan: str
+    status: str
+    monthly_limit: int
+    is_unlimited: bool
+
+
+class UpgradeRequest(BaseModel):
+    plan: str
+
+
+class UsageRead(BaseModel):
+    plan: str
+    reservations_this_month: int
+    monthly_limit: int
+    is_unlimited: bool

backend/app/modules/billing/service.py

@@ -0,0 +1,59 @@
+from datetime import date
+
+from fastapi import HTTPException, status
+from sqlalchemy import and_, func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.modules.billing.schemas import PLAN_LIMITS, PlanRead, UsageRead
+from app.modules.business.models import Business
+from app.modules.business.service import get_business
+from app.modules.reservations.models import Reservation
+
+VALID_PLANS = set(PLAN_LIMITS.keys())
+
+
+async def get_plan(db: AsyncSession, business_id: int) -> PlanRead:
+    business = await get_business(db, business_id)
+    limit = PLAN_LIMITS[business.plan]
+    return PlanRead(
+        plan=business.plan,
+        status=business.status,
+        monthly_limit=limit,
+        is_unlimited=limit == -1,
+    )
+
+
+async def upgrade_plan(db: AsyncSession, business_id: int, new_plan: str) -> PlanRead:
+    if new_plan not in VALID_PLANS:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Plan inválido. Opciones: {', '.join(VALID_PLANS)}",
+        )
+    business = await get_business(db, business_id)
+    business.plan = new_plan
+    await db.commit()
+    await db.refresh(business)
+    return await get_plan(db, business_id)
+
+
+async def get_usage(db: AsyncSession, business_id: int) -> UsageRead:
+    business = await get_business(db, business_id)
+    month_start = date.today().replace(day=1)
+
+    result = await db.execute(
+        select(func.count(Reservation.id)).where(
+            and_(
+                Reservation.business_id == business_id,
+                Reservation.date >= month_start,
+            )
+        )
+    )
+    count = result.scalar_one()
+    limit = PLAN_LIMITS[business.plan]
+
+    return UsageRead(
+        plan=business.plan,
+        reservations_this_month=count,
+        monthly_limit=limit,
+        is_unlimited=limit == -1,
+    )