Validates the Q2 privacy features (shield/deshield, private-to-private transfers,
existing-account crediting, group-owned accounts, and private PDAs) against the
token and ata program flows, which previously ran almost entirely in public
context. Adds the key_protocol dependency for GMS-based group-account tests and
introduces a docs/privacy-test-matrix.md tracker mapping each program/instruction/
privacy-dimension combination to pass, fail, or not-expressible, with root-cause
findings for each gap (notably that private PDAs are structurally unsupported by
any program currently deriving addresses via for_public_pda).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
