feat: 웹사이트 표준화 검사 도구 구현

- 4개 검사 엔진: HTML/CSS, 접근성(WCAG), SEO, 성능/보안 (총 50개 항목)
- FastAPI 백엔드 (9개 API, SSE 실시간 진행, PDF/JSON 리포트)
- Next.js 15 프론트엔드 (6개 페이지, 29개 컴포넌트, 반원 게이지 차트)
- Docker Compose 배포 (Backend:8011, Frontend:3011, MongoDB:27022, Redis:6392)
- 전체 테스트 32/32 PASS

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/models/schemas.py

@@ -0,0 +1,179 @@
+"""
+Pydantic models for request/response validation and serialization.
+"""
+
+from pydantic import BaseModel, Field, HttpUrl
+from typing import Optional
+from datetime import datetime
+from enum import Enum
+
+
+# --- Enums ---
+
+class InspectionStatus(str, Enum):
+    RUNNING = "running"
+    COMPLETED = "completed"
+    ERROR = "error"
+
+
+class Severity(str, Enum):
+    CRITICAL = "critical"
+    MAJOR = "major"
+    MINOR = "minor"
+    INFO = "info"
+
+
+class CategoryName(str, Enum):
+    HTML_CSS = "html_css"
+    ACCESSIBILITY = "accessibility"
+    SEO = "seo"
+    PERFORMANCE_SECURITY = "performance_security"
+
+
+# --- Request ---
+
+class StartInspectionRequest(BaseModel):
+    url: HttpUrl
+
+
+# --- Core Data Models ---
+
+class Issue(BaseModel):
+    code: str
+    category: str
+    severity: Severity
+    message: str
+    element: Optional[str] = None
+    line: Optional[int] = None
+    suggestion: str
+    wcag_criterion: Optional[str] = None
+
+
+class CategoryResult(BaseModel):
+    score: int = Field(ge=0, le=100)
+    grade: str
+    total_issues: int
+    critical: int = 0
+    major: int = 0
+    minor: int = 0
+    info: int = 0
+    issues: list[Issue] = []
+    # Category-specific fields
+    wcag_level: Optional[str] = None
+    meta_info: Optional[dict] = None
+    sub_scores: Optional[dict] = None
+    metrics: Optional[dict] = None
+
+
+class IssueSummary(BaseModel):
+    total_issues: int
+    critical: int
+    major: int
+    minor: int
+    info: int
+
+
+# --- Response Models ---
+
+class StartInspectionResponse(BaseModel):
+    inspection_id: str
+    status: str = "running"
+    url: str
+    stream_url: str
+
+
+class InspectionResult(BaseModel):
+    inspection_id: str
+    url: str
+    status: InspectionStatus
+    created_at: datetime
+    completed_at: Optional[datetime] = None
+    duration_seconds: Optional[float] = None
+    overall_score: int = Field(ge=0, le=100)
+    grade: str
+    categories: dict[str, CategoryResult]
+    summary: IssueSummary
+
+
+class InspectionResultResponse(BaseModel):
+    """Response model for GET /api/inspections/{id} (without nested issues)."""
+    inspection_id: str
+    url: str
+    status: InspectionStatus
+    created_at: datetime
+    completed_at: Optional[datetime] = None
+    duration_seconds: Optional[float] = None
+    overall_score: int = Field(ge=0, le=100)
+    grade: str
+    categories: dict[str, CategoryResult]
+    summary: IssueSummary
+
+
+class IssueListResponse(BaseModel):
+    inspection_id: str
+    total: int
+    filters: dict
+    issues: list[Issue]
+
+
+class InspectionListItem(BaseModel):
+    inspection_id: str
+    url: str
+    created_at: datetime
+    overall_score: int
+    grade: str
+    total_issues: int
+
+
+class PaginatedResponse(BaseModel):
+    items: list[InspectionListItem]
+    total: int
+    page: int
+    limit: int
+    total_pages: int
+
+
+class TrendDataPoint(BaseModel):
+    inspection_id: str
+    created_at: datetime
+    overall_score: int
+    html_css: int
+    accessibility: int
+    seo: int
+    performance_security: int
+
+
+class TrendResponse(BaseModel):
+    url: str
+    data_points: list[TrendDataPoint]
+
+
+class HealthResponse(BaseModel):
+    status: str
+    timestamp: str
+    services: dict[str, str]
+
+
+# --- Utility functions ---
+
+def calculate_grade(score: int) -> str:
+    """Calculate letter grade from numeric score."""
+    if score >= 90:
+        return "A+"
+    if score >= 80:
+        return "A"
+    if score >= 70:
+        return "B"
+    if score >= 60:
+        return "C"
+    if score >= 50:
+        return "D"
+    return "F"
+
+
+def calculate_overall_score(categories: dict[str, CategoryResult]) -> int:
+    """Calculate overall score as simple average of category scores."""
+    scores = [cat.score for cat in categories.values()]
+    if not scores:
+        return 0
+    return round(sum(scores) / len(scores))