docs: add Azure scanner validation and testing framework

[parthrohit22]

What does this PR do?

Implements the documentation framework proposed in Issue #131 for Azure scenario testing and scanner verification.

This PR introduces a contributor-focused validation workflow for OpenShield that documents how scanner findings should be validated against intentionally vulnerable Azure resources and tracked through the platform lifecycle.

Validation lifecycle:

Azure Resource → Scanner → Database → API → Frontend

Type of change

• Documentation
• New scan rule
• Remediation playbook
• Bug fix
• Dashboard/front-end work
• API endpoint
• Compliance mapping

Changes included

Validation Plan

Added:

• docs/VALIDATION_PLAN.md

Includes:

• Validation objectives
• Scope and non-goals
• Phased validation roadmap
• Contributor workflow
• End-to-end validation lifecycle

Scanner Validation Guide

Added:

• docs/validation/SCANNER_VALIDATION.md

Includes:

• Scanner architecture overview
• Dynamic rule-loading behavior
• Rule validation strategy
• Rule coverage categorization
• Validation priorities and known considerations

Azure Scenario Guide

Added:

• docs/validation/AZURE_SCENARIOS.md

Includes low-cost Azure validation scenarios for:

• AZ-STOR-001
• AZ-NET-001
• AZ-NET-002
• AZ-KV-002
• AZ-KV-004

Each scenario documents:

• Expected finding
• Validation workflow
• Cleanup procedure
• Result tracking placeholders

Test Results Framework

Updated:

• docs/validation/TEST_RESULTS.md

Includes:

• Validation status tracking
• Evidence collection guidance
• Pass/fail tracking
• False positive / false negative tracking
• Retest workflow

Acceptance Criteria Coverage

• Validation framework documented
• Azure test scenarios documented
• Test result tracking template created
• Contributor workflow documented
• No Azure credentials committed
• No production resources used

Testing

• Documentation reviewed
• Rule references verified against current scanner rules
• Validation results remain marked as Pending
• No production code modified

Related Issue

Closes #131

Notes

This PR does not execute Azure validation.

This PR establishes the documentation and process required for future Azure scenario testing, scanner verification, API validation, database validation, and frontend validation activities.

[Vishnu2707]

@ritiksah141 , @TFT444 , please review the PR.