PainAggregator and SolutionGenerator were in-memory only, losing all
data on restart. Add PainStorage module with SQLite backend (4 tables),
dual-write strategy (hot cache + durable), and startup cache warming.
- New: pain_storage.rs — SQLite CRUD for pain_points, pain_evidence,
proposals, proposal_steps with schema initialization
- Modified: pain_aggregator.rs — global PAIN_STORAGE singleton,
init_pain_storage() for startup, dual-write in merge_or_create/update
- Modified: solution_generator.rs — same dual-write pattern via
global PAIN_STORAGE
- 20 tests passing (10 storage + 10 aggregator)
- Add TODO to PainAggregator documenting in-memory-only data limitation
- Remove unused `use serde::Serialize` import from a2a.rs (already clean)
- ProposalsSection: trigger refresh on error instead of silent catch
- useButlerInsights: collect all errors instead of overwriting
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
