Initial import: shopdb-flask multi-site asset platform

Flask + Vue rewrite of the classic-ASP shopdb, built as a plugin
framework so sister GE Aerospace sites can adopt it. Product version
0.7.0-pre-0.8.0, plugin contract 0.11.0, 966 backend tests.

Key entry points:
- docs/INSTALL-WINDOWS-IIS.md - tested Windows + IIS install runbook
  (own-site and subpath deployment methods)
- docs/PILOT-DEPLOY.md - production pilot: stand up + import + verify
- docs/IMPORT-API.md - schema-agnostic legacy data import contract
- scripts/site_imports/wjf/ - West Jefferson reference import loader
- docs/adr/ - twelve accepted architecture decision records

shopdb/utils/responses.py

@@ -0,0 +1,175 @@
+"""Standardized API response helpers."""
+
+from flask import jsonify, make_response
+from typing import Any, Dict, List
+from datetime import datetime, timezone
+import uuid
+
+
+class ErrorCodes:
+    """Standard error codes."""
+
+    VALIDATION_ERROR = 'VALIDATION_ERROR'
+    NOT_FOUND = 'NOT_FOUND'
+    UNAUTHORIZED = 'UNAUTHORIZED'
+    FORBIDDEN = 'FORBIDDEN'
+    CONFLICT = 'CONFLICT'
+    INTERNAL_ERROR = 'INTERNAL_ERROR'
+    BAD_REQUEST = 'BAD_REQUEST'
+    PLUGIN_ERROR = 'PLUGIN_ERROR'
+
+
+def api_response(
+    data: Any = None,
+    message: str = None,
+    status: str = 'success',
+    meta: Dict = None,
+    http_code: int = 200
+):
+    """
+    Create standardized API response.
+
+    Response format:
+    {
+        "status": "success" | "error",
+        "data": {...} | [...],
+        "message": "Optional message",
+        "meta": {
+            "timestamp": "2025-01-12T...",
+            "request_id": "uuid"
+        }
+    }
+    """
+    response = {
+        'status': status,
+        'meta': {
+            'timestamp': datetime.now(timezone.utc).replace(tzinfo=None).isoformat() + 'Z',
+            'requestid': str(uuid.uuid4())[:8],
+            **(meta or {})
+        }
+    }
+
+    if data is not None:
+        response['data'] = data
+
+    if message:
+        response['message'] = message
+
+    return make_response(jsonify(response), http_code)
+
+
+def success_response(
+    data: Any = None,
+    message: str = None,
+    meta: Dict = None,
+    http_code: int = 200
+):
+    """Success response helper."""
+    return api_response(
+        data=data,
+        message=message,
+        meta=meta,
+        status='success',
+        http_code=http_code
+    )
+
+
+def error_response(
+    code: str,
+    message: str,
+    details: Dict = None,
+    http_code: int = 400
+):
+    """Error response helper.
+
+    Response format:
+    {
+        "status": "error",
+        "data": {
+            "error": {
+                "code": "VALIDATION_ERROR",
+                "message": "Human-readable message",
+                "details": {...}
+            }
+        },
+        "meta": {
+            "timestamp": "...",
+            "requestid": "..."
+        }
+    }
+    """
+    error_data = {
+        'code': code,
+        'message': message
+    }
+    if details:
+        error_data['details'] = details
+
+    return api_response(
+        data={'error': error_data},
+        status='error',
+        http_code=http_code
+    )
+
+
+def api_error(
+    message: str,
+    code: str = ErrorCodes.BAD_REQUEST,
+    details: Dict = None,
+    http_code: int = 400
+):
+    """
+    Simplified error response helper.
+
+    Args:
+        message: Human-readable error message
+        code: Error code (default BAD_REQUEST)
+        details: Optional error details
+        http_code: HTTP status code (default 400)
+    """
+    return error_response(code=code, message=message, details=details, http_code=http_code)
+
+
+def paginated_response(
+    items: List,
+    page: int,
+    per_page: int,
+    total: int,
+    schema=None
+):
+    """Paginated list response.
+
+    Response format:
+    {
+        "status": "success",
+        "data": [...],
+        "meta": {
+            "pagination": {
+                "page": 1,
+                "perpage": 20,
+                "total": 150,
+                "totalpages": 8,
+                "hasnext": true,
+                "hasprev": false
+            }
+        }
+    }
+    """
+    total_pages = (total + per_page - 1) // per_page if per_page > 0 else 0
+
+    if schema:
+        items = schema.dump(items, many=True)
+
+    return api_response(
+        data=items,
+        meta={
+            'pagination': {
+                'page': page,
+                'perpage': per_page,
+                'total': total,
+                'totalpages': total_pages,
+                'hasnext': page < total_pages,
+                'hasprev': page > 1
+            }
+        }
+    )