Add draft threat model + SECURITY.md + AGENTS.md for security-model discoverability#397

PragmaTwice merged 3 commits into

apache:unstableapache/kvrocks-controller:unstablefrom

potiuk:asf-security/threat-model-2026-05-31potiuk/kvrocks-controller:asf-security/threat-model-2026-05-31Copy head branch name to clipboard