chore(openspec): propose mobile stack decision (RN/Expo vs Flutter)

openspec/changes/2025-11-17-mobile-stack-decision/proposal.md

@@ -0,0 +1,48 @@
+# Proposal: Mobile Stack Decision (Android/iOS)
+
+Status: draft
+Authors: Platform Team
+Owners: Architecture Lead, Mobile Lead
+Created: 2025-11-17
+Scope: spec
+Related: openspec/specs/architecture.md
+
+Summary
+- Decide between React Native + Expo vs Flutter for Android/iOS with full accessibility parity, strong privacy posture, and long-term maintainability.
+
+Motivation
+- Commit to a mobile stack that accelerates delivery while meeting a11y, compliance, and performance requirements across all features.
+
+Goals / Non‑Goals
+- Goals: select stack, document rationale, list enabling libraries/tooling, define migration/rollback path.
+- Non‑Goals: finalize design system visuals (handled in later proposals).
+
+Evaluation Criteria
+- Accessibility: VoiceOver/TalkBack parity; dynamic type; reduced motion; larger text support.
+- Performance: cold start, nav latency, list virtualization; p95 targets defined in architecture spec.
+- Ecosystem: first‑party support, community libs for a11y, storage, media, push, payments.
+- Compliance & Security: secure storage, network stack, logging redaction, crash reporting controls.
+- Developer Experience: CI/CD, hot reload, E2E testing, upgrade cadence.
+
+Options
+- React Native + Expo (with Reanimated, RN‑Skia optional, TypeScript, Detox/E2E)
+- Flutter (Dart, integration_test/E2E, Impeller renderer)
+
+Risks & Mitigations
+- Accessibility gaps → add native modules or platform adapters; enforce CI a11y gates.
+- Perf regressions → profiling budgets and regression tests.
+
+Rollout Plan
+- Pilot with Forum MVP screens; run A11y + perf checks; make decision.
+
+Test Plan
+- Prototype forum list/thread/post; run a11y audits; measure startup and interaction latencies.
+
+Acceptance Criteria
+- Decision recorded with rationale; pilot results included; sign‑off from a11y and compliance.
+
+Slash Commands
+- `/review areas=mobile,accessibility,security`
+- `/apply spec=openspec/specs/architecture.md`
+- `/archive link=<PR>`
+