feat: T03 backend core – FastAPI + DB models + Equipment API + Redis cache + health + tests

- FastAPI app with CORS, lifespan handlers
- Pydantic Settings config (DB, Redis, CORS, SMTP, JWT, Rentman)
- SQLAlchemy async engine + session (DeclarativeBase)
- 6 DB models: EquipmentCache, RentalRequest, RentalRequestItem, Contact, AdminUser, SyncLog
- Pydantic schemas: EquipmentItem, EquipmentDetail, PaginatedEquipment, ContactCreate, ContactResponse
- Redis cache helper: set/get/delete_pattern, rate limiting, equipment key builders
- Equipment router: list (search/category/sort/pagination), detail, categories – all cached
- Contact router: POST with Pydantic validation + rate limiting (5/min)
- Health router: GET /api/health with DB + Redis status
- 28 pytest tests (all pass, 90% coverage)
- Dockerfile, requirements.txt, pytest.ini, test_report.md

backend/app/schemas/__init__.py

@@ -0,0 +1,6 @@
+"""Pydantic schemas package."""
+
+from app.schemas.contact import ContactCreate, ContactResponse
+from app.schemas.equipment import EquipmentDetail, EquipmentItem, PaginatedEquipment
+
+__all__ = ["ContactCreate", "ContactResponse", "EquipmentDetail", "EquipmentItem", "PaginatedEquipment"]

backend/app/schemas/contact.py

@@ -0,0 +1,27 @@
+"""Pydantic schemas for contact form."""
+
+from pydantic import BaseModel, EmailStr, Field, model_validator
+
+
+class ContactCreate(BaseModel):
+    """Contact form input schema."""
+
+    name: str = Field(..., min_length=1, max_length=255)
+    email: EmailStr
+    phone: str | None = Field(None, max_length=64)
+    message: str = Field(..., min_length=1, max_length=5000)
+    privacy_consent: bool = Field(..., description="Must be True")
+
+    @model_validator(mode="after")
+    def consent_must_be_true(self) -> "ContactCreate":
+        """Reject submissions where privacy_consent is not True."""
+        if not self.privacy_consent:
+            raise ValueError("privacy_consent must be True")
+        return self
+
+
+class ContactResponse(BaseModel):
+    """Contact form response."""
+
+    success: bool
+    message: str = "Kontakt-Anfrage erfolgreich gesendet."

backend/app/schemas/equipment.py

@@ -0,0 +1,50 @@
+"""Pydantic schemas for equipment endpoints."""
+
+from decimal import Decimal
+
+from pydantic import BaseModel, ConfigDict
+
+
+class EquipmentItem(BaseModel):
+    """Equipment item for list responses."""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    rentman_id: str
+    name: str
+    number: str | None = None
+    category: str | None = None
+    description: str | None = None
+    image_url: str | None = None
+    rental_price: Decimal | None = None
+    available: bool = True
+
+
+class EquipmentDetail(BaseModel):
+    """Equipment detail with full specifications."""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    rentman_id: str
+    name: str
+    number: str | None = None
+    category: str | None = None
+    subcategory: str | None = None
+    description: str | None = None
+    specifications: dict | None = None
+    images: list | None = None
+    rental_price: Decimal | None = None
+    brand: str | None = None
+    available: bool = True
+
+
+class PaginatedEquipment(BaseModel):
+    """Paginated response for equipment list."""
+
+    items: list[EquipmentItem]
+    total: int
+    page: int
+    page_size: int
+    total_pages: int