docs: split CLAUDE.md into docs/{development,deployment,history/fase-*}

CLAUDE.md shrinks to rules + status + index (175 lines, down from 476).
Dev setup, prod deploy, and per-phase build records move to docs/.
Gotchas regrouped by domain (auth, frontend, PWA, testing, backend, deploy,
platform) and unnumbered so they don't drift as new ones land.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/history/fase-2a.md

@@ -0,0 +1,8 @@
+# Fase 2a — what has been built
+
+- `supabase/migrations/005_shopping.sql` — `shopping_lists`, `shopping_items`, RLS, `list_collective_id()` helper, pg_cron jobs (archive completed > 7d, purge deleted > 7d)
+- `supabase/migrations/006_item_frequency.sql` — `item_frequency` table, `fn_record_item_frequency` trigger (SECURITY DEFINER, fires on every `shopping_items` INSERT)
+- `apps/web/src/lib/stores/lists.ts` — shopping lists store (optimistic CRUD) + item operations + suggestion fetching
+- `apps/web/src/lib/components/ItemSuggestions.svelte` — frequency chips with active-prefix highlighting
+- `apps/web/src/routes/(app)/lists/+page.svelte` — overview: featured card + 2-col grid + completed section + trash view (sticky input replaced by masthead "New list" button in Fase 5.8)
+- `apps/web/src/routes/(app)/lists/[id]/+page.svelte` — list detail: items with checkbox, qty stepper (−/N/+), inline edit, swipe-to-reveal-delete (touch) + hover delete (desktop), drag & drop reorder via `svelte-dnd-action`, sticky add form with `ItemSuggestions`