Cross-platform parity audit and GA release

[MA1002643]

Context

Brief §4.4 is absolute: no feature may exist on one platform and be missing on another. With web, PWA, three desktop shells and two mobile wrappers live, this issue is the systematic proof — and the GA gate.

Scope

• Parity matrix: every user-facing capability (from the command registry + route map — the same enumeration the palette CI check uses) × every platform (web ×4 browsers, installed PWA, Windows/macOS/Linux shells, Android/iOS wrappers); each cell verified automated-where-possible, manual otherwise; honest platform-limit annotations (e.g. iOS web push pre-install) reviewed against §4.4 and either resolved or explicitly accepted with rationale.
• Consistency audit (§7.1/§7.4): visual regression sweep across platforms at shared breakpoints; interaction-behaviour spot checks (gestures, modals, toasts) confirming no per-OS divergence.
• GA readiness review: all P0/P1 issues closed or waived with rationale; security-review criticals confirmed closed; SLO dashboards green 14 consecutive days; support/feedback channel live; rollback and incident runbooks current.
• GA release: coordinated version across web + stores, release notes, README/docs refreshed from their static-site past to the shipped platform.

Acceptance criteria

• Parity matrix complete with zero unaccepted gaps; accepted annotations each carry a written rationale and a follow-up issue where applicable.
• Cross-platform visual/interaction audit signed off with evidence links.
• GA checklist (above) fully green; the release shipped and tagged v1.0.0 (Changesets), announcement published.
• Post-GA review scheduled (30 days) with the DEC-002 cost review triggers.

Technical notes

The parity matrix should be generated, not hand-written — derive rows from the command registry and route manifest so the audit can be re-run every release, keeping §4.4 true beyond GA.

Dependencies

Depends on #63, #64, #61, #62, #45.