feat: add demand page modules and admin endpoints

Add full backend support for a demand request page, including:
- New database models for demand hero, feature cards, form configuration, and product recommendations
- Alembic migration for the new tables
- Default seed data for demand page components
- Public site config endpoint exposing demand data
- Admin CRUD operations and configuration for demand modules
- Extended lead query filters for source page, keyword, and date range
- Updated Pydantic schemas for lead query parameters
- Comprehensive test coverage for all new endpoints

app/schemas.py

@@ -1,6 +1,6 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 from typing import Literal
-from pydantic import BaseModel, EmailStr, Field, field_validator
+from pydantic import BaseModel, EmailStr, Field, ValidationInfo, field_validator
 
 
 ProductStatus = Literal["draft", "published", "archived"]
@@ -115,8 +115,23 @@ class AdminProductQuery(BaseModel):
 
 class LeadQuery(BaseModel):
     status: LeadStatus | None = None
+    sourcePage: str | None = None
+    keyword: str | None = None
+    createdFrom: datetime | None = None
+    createdTo: datetime | None = None
     take: int = Field(default=100, ge=1, le=200)
 
+    @field_validator("createdFrom", "createdTo", mode="before")
+    @classmethod
+    def parse_date_only_range(cls, value, info: ValidationInfo):
+        if isinstance(value, str) and len(value) == 10:
+            try:
+                parsed = datetime.strptime(value, "%Y-%m-%d")
+                return parsed + timedelta(days=1) if info.field_name == "createdTo" else parsed
+            except ValueError:
+                return value
+        return value
+
 
 class SiteConfigPatchIn(BaseModel):
     title: str | None = None
@@ -135,6 +150,15 @@ class SiteConfigPatchIn(BaseModel):
     priceAmount: int | None = Field(default=None, ge=0)
     priceUnit: str | None = None
     tags: list[str] | None = None
+    steps: list[str] | None = None
+    destinationLabel: str | None = None
+    destinationPlaceholder: str | None = None
+    phoneLabel: str | None = None
+    phonePlaceholder: str | None = None
+    noteLabel: str | None = None
+    notePlaceholder: str | None = None
+    submitLabel: str | None = None
+    chips: list[str] | None = None
     productIds: list[str] | None = None
     status: str | None = None
     startsAt: datetime | None = None