Complete privacy and support-data policy

[KeyffMS]

What changed

• expand PRIVACY.md to describe all local data read/stored by SightAdapt;
• document settings inspection, export, deletion and reset;
• state the current absence of telemetry, analytics, remote crash reporting, diagnostic upload, cloud accounts and automatic update checks;
• define redaction and private-reporting guidance for paths, settings, logs, screenshots and recordings;
• identify KeyffMS / aiteracja.pl as the controller for privately received support data and define the current contact route;
• define access, purpose, normal 90-day retention and deletion handling for privately submitted support material;
• require privacy review before new telemetry, uploads, network services or persistent data collection;
• align README and contribution guidance with the policy.

Scope

Documentation and governance only. No application behavior is changed.

Closes #86.