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/models.py

@@ -0,0 +1,65 @@
+from datetime import date, time
+
+from sqlalchemy import (
+    Column,
+    Date,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Time,
+    func,
+)
+from sqlalchemy.dialects.postgresql import ARRAY
+from sqlalchemy.orm import relationship
+
+from app.core.database import Base
+
+
+class Business(Base):
+    __tablename__ = "businesses"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, nullable=False)
+    type = Column(String, nullable=False)
+    timezone = Column(String, nullable=False, default="UTC")
+    status = Column(
+        Enum("trial", "active", "suspended", name="business_status"),
+        nullable=False,
+        default="trial",
+    )
+    plan = Column(
+        Enum("free", "basic", "pro", name="business_plan"),
+        nullable=False,
+        default="free",
+    )
+    meta_business_id = Column(String, nullable=True)
+    whatsapp_phone_number_id = Column(String, nullable=True, unique=True)
+    whatsapp_access_token = Column(String, nullable=True)
+    created_at = Column(Date, server_default=func.current_date())
+
+    users = relationship("User", back_populates="business", cascade="all, delete-orphan")
+    config = relationship("BusinessConfig", back_populates="business", uselist=False)
+    reservations = relationship("Reservation", back_populates="business")
+
+
+class BusinessConfig(Base):
+    __tablename__ = "business_configs"
+
+    id = Column(Integer, primary_key=True, index=True)
+    business_id = Column(
+        Integer, ForeignKey("businesses.id", ondelete="CASCADE"), nullable=False, unique=True
+    )
+    open_days = Column(ARRAY(Integer), nullable=False, default=list)
+    open_time = Column(Time, nullable=False, default=time(9, 0))
+    close_time = Column(Time, nullable=False, default=time(18, 0))
+    slot_duration = Column(Integer, nullable=False, default=60)
+    max_per_slot = Column(Integer, nullable=False, default=1)
+    blocked_dates = Column(ARRAY(Date), nullable=False, default=list)
+    assistant_name = Column(String, nullable=False, default="Hermes")
+    tone = Column(
+        Enum("formal", "casual", name="assistant_tone"), nullable=False, default="formal"
+    )
+    welcome_message = Column(String, nullable=True)
+
+    business = relationship("Business", back_populates="config")