Update session log and component registry for CoffinsStep rewrite

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/memory/session-log.md

@@ -26,6 +26,38 @@ Each entry follows this structure:
 
 ## Sessions
 
+### Session 2026-03-31a — CoffinsStep rewrite: grid-sidebar ecommerce layout
+
+**Agent(s):** Claude Opus 4.6 (1M context)
+
+**Work completed:**
+- **CoffinsStep complete rewrite** — transformed from wide-form card grid into a two-column ecommerce layout matching the live site pattern:
+  - **Layout:** `grid-sidebar` with viewport-locked independent scrolling (sidebar scrollbar on hover, grid always scrollable)
+  - **Sidebar:** heading, conditional allowance info bubble, category menu with expandable subcategories (Collapse animation, chevron rotation), dual-knob price range slider with editable text inputs (commit on blur/Enter), sort by dropdown (popularity, price asc/desc), clear all filters link, save-and-exit link at bottom
+  - **Grid:** 3-col coffin card grid with `CoffinCard` internal component — thumbnail hover preview (hover swaps main image, leave reverts), equal-height cards via flex layout, subtle background for white-bg product photos, "Most Popular" badge, colour count text
+  - **Navigation:** card click fires `onSelectCoffin(id)` to navigate to CoffinDetailsStep — no Continue button
+  - **Pagination:** 20 coffins per page max (`pageSize` prop, enforced via slice)
+- **WizardLayout `grid-sidebar` update** — wider sidebar (28%), `overflowX: hidden` (no horizontal scroll), `overflowY: auto` at all breakpoints, responsive viewport-lock (desktop only)
+- **Removed:** `selectedCoffinId`, `CoffinsStepErrors`, `CoffinPriceRange`, `onContinue`, `loading` props
+- **Added:** `onSelectCoffin`, `CoffinSortBy`, `pageSize`, `minPrice`/`maxPrice`, `thumbnails`/`colourCount` on Coffin, `children` on `CoffinCategory`
+
+**Decisions made:**
+- Card click navigates directly to details (no selection + continue pattern) — matches ecommerce browsing UX
+- Categories support one level of subcategories — parent click loads all and expands children, child click refines
+- Price slider with editable text inputs — commits on blur/Enter to avoid per-keystroke re-renders
+- 20 coffins per page default — enforced in component via slice
+- Allowance info bubble is conditional (omit prop = no bubble) — some packages don't have coffin allowances
+
+**Open questions:**
+- None
+
+**Next steps:**
+- Continue page feedback: AdditionalServicesStep, SummaryStep, PaymentStep, ConfirmationStep
+- Retroactive review Phase 3 (organisms) still pending
+- Batch a11y fix (aria-describedby + aria-invalid) deferred
+
+---
+
 ### Session 2026-03-30e — Page feedback: VenueServices, Crematorium, Cemetery rewrites
 
 **Agent(s):** Claude Opus 4.6 (1M context)