Define Privacy Requirements for 3rd Party Extensions

## Description

Define privacy requirements for 3rd party extensions to ensure compliance with GDPR, Microsoft privacy policies, and other privacy regulations.

## Acceptance Criteria

- Data collection guidelines documented
- PII (Personally Identifiable Information) handling requirements defined
- GDPR/privacy compliance checklist created
- User consent requirements specified
- Privacy documentation accessible to extension authors
- Privacy impact assessment process defined
- Data breach notification procedures established

## Key Privacy Areas

1. **Data Collection Guidelines**
- What data can be collected
- Data minimization principles
- Purpose limitation requirements
- Transparency requirements

2. **PII Handling Requirements**
- PII identification and classification
- Encryption requirements
- Data retention policies
- Data deletion procedures
- Cross-border data transfer restrictions

3. **GDPR Compliance**
- Right to access
- Right to erasure
- Right to data portability
- Consent management
- Privacy by design principles

4. **User Consent**
- When consent is required
- How to obtain valid consent
- Consent withdrawal mechanisms
- Documentation of consent

## Parent Issue

This is part of the 3rd Party Extension Submission Process epic.

## Labels

extensions, privacy, documentation