Add BeanFlows MVP: coffee analytics dashboard, API, and web app

- Fix pipeline granularity: add market_year to cleaned/serving SQL models
- Add DuckDB data access layer with async query functions (analytics.py)
- Build Chart.js dashboard: supply/demand, STU ratio, top producers, YoY table
- Add country comparison page with multi-select picker
- Replace items CRUD with read-only commodity API (list, metrics, countries, CSV)
- Configure BeanFlows plan tiers (Free/Starter/Pro) with feature gating
- Rewrite public pages for coffee market intelligence positioning
- Remove boilerplate items schema, update health check for DuckDB
- Add test suite: 139 tests passing (dashboard, API, billing)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/.copier-answers.yml

@@ -0,0 +1,10 @@
+# Changes here will be overwritten by Copier; NEVER EDIT MANUALLY
+_commit: v0.3.0
+_src_path: /home/Deeman/Projects/quart_saas_boilerplate
+author_email: hendrik@beanflows.coffee
+author_name: Hendrik Deeman
+base_url: https://beanflows.coffee
+description: Commodity analytics for coffee traders
+payment_provider: paddle
+project_name: BeanFlows
+project_slug: beanflows