Replaces the two `pricing_*_tiers_json` blobs and five `first_session_discount_*` keys in app_config with dedicated `pricing_tiers` and `pricing_promotions` tables plus matching `_history` audit tables. UUID PKs, UNIQUE(mode, minutes) natural-key constraint, optimistic-lock via `updated_at` token returning 409 STALE_WRITE on conflicts. Every mutation writes a history row capturing the operator (changed_by from request.auth.userId) and change_kind. CC SettingsPage replaces the JSON-textarea editors with per-row tables — add / edit / soft-delete / reactivate / reorder, plus a buffered first-session discount form with the same optimistic-lock contract. `minutes` and `mode` are read-only on edit since they form the natural key; operators soft-delete and recreate to change duration. Stage 5 fixes a latent leak: `client.payment.routes.js` had its own local `readDiscountConfig` that still read from app_config — would have silently fallen to hardcoded defaults once the legacy rows were deleted. Now reads from pricing_promotions via the shared service helper, so CC edits to the first- session discount affect actual payment pricing on the next request. Customer-facing GET /api/client/chat/pricing shape unchanged (id values are now UUIDs instead of "5"/"12"/"60" but lookups happen by (mode, minutes), so no app changes needed). 27 new backend tests, all green. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
20 KiB
20 KiB