Housekeeping: record V2 owner decisions (defer all three) + archive June audit docs

[ElbertePlinio]

Unfreeze the project and stop the audit-doc spiral.

• Record owner answers (approved 2026-07-08) in docs/plans/2026-06-20-v2-owner-decision-packet.md: authorship provenance = unavailable for V2; provider/session evidence = deferred; Droid/Bubblewrap provider-session rerun = deferred (local sandbox replay stays the V2 evidence level)
• Archive the June 19–20 audit/packet docs to docs/plans/old/ — the master spec + GitHub issues become the only living status
• Update master-spec checkboxes that are actually done (repeated hidden flake checks, etc.) and mark cross-framework/security as later phases sequenced after Flutter v1.0

[ElbertePlinio]

Parent plan: #10