Cyber/CY017- Resuable Logging Function

[Sayek17]

Added CY017 Reusable Logging Function/Module Design. Now working my way through TypeScript/Express implementation for the reusable logging module to track suspicious activity in the system. Previously added CY010 Spam Alert Prevention, CY010 Document Rules and Revised API Design.

[Sayek17]

CY017: Reusable security logging function - implementation

This PR delivers the reusable security logging function specified in the CY017 design document as working TypeScript for the Node.js + Express stack. The component records security decisions made by other backend controls (authentication, JWT validation, RBAC, validation, rate limiting, throttling, duplicate detection, monitoring). It is intentionally observational ; it does not decide whether to block, delay, accept, flag or escalate a request. Those decisions belong to the controls that own them.

The intent is to land the implementation in dev so the rest of the cybersecurity team can call it from middleware/controllers.

What is in this PR

File	Purpose
securityLogTypes.ts	Single source of truth for event types, severity, outcome, rule references, reason sub-classifiers, the SecurityLogRecord shape and helper input shapes.
securityLogger.ts	logSecurityEvent() core plus eight typed helpers, reason-specific defaults tables, sanitisation.
logTransport.ts	LogTransport interface and the default ConsoleJsonTransport.
expressLogContext.ts	fromRequest() extracts a safe Express context (ip_address, endpoint, method, user_id, role, request_id).
index.ts	Convenience re-export so callers can import { logAuthFailure, fromRequest } from '.../logging'.
demo.ts	Runnable demo covering all eight events, every reason sub-classifier and the sanitisation case.
README.md	Per-file responsibilities, helper signatures, NDJSON output format, transport replacement, safety notes.
package.json, tsconfig.json	TypeScript toolchain -typecheck, build, demo.