Add Phase 1A-C + ICE warehouse stocks: prices, methodology, pipeline automation

Phase 1A — KC=F Coffee Futures Prices:
- New extract/coffee_prices/ package (yfinance): downloads KC=F daily OHLCV,
  stores as gzip CSV with SHA256-based idempotency
- SQLMesh models: raw/coffee_prices → foundation/fct_coffee_prices →
  serving/coffee_prices (with 20d/50d SMA, 52-week high/low, daily return %)
- Dashboard: 4 metric cards + dual-line chart (close, 20d MA, 50d MA)
- API: GET /commodities/<ticker>/prices

Phase 1B — Data Methodology Page:
- New /methodology route with full-page template (base.html)
- 6 anchored sections: USDA PSD, CFTC COT, KC=F price, ICE warehouse stocks,
  data quality model, update schedule table
- "Methodology" link added to marketing footer

Phase 1C — Automated Pipeline:
- supervisor.sh updated: runs extract_cot, extract_prices, extract_ice in
  sequence before transform
- Webhook failure alerting via ALERT_WEBHOOK_URL env var (ntfy/Slack/Telegram)

ICE Warehouse Stocks:
- New extract/ice_stocks/ package (niquests): normalizes ICE Report Center CSV
  to canonical schema, hash-based idempotency, soft-fail on 404 with guidance
- SQLMesh models: raw/ice_warehouse_stocks → foundation/fct_ice_warehouse_stocks
  → serving/ice_warehouse_stocks (30d avg, WoW change, 52w drawdown)
- Dashboard: 4 metric cards + line chart (certified bags + 30d avg)
- API: GET /commodities/<code>/stocks

Foundation:
- dim_commodity: added ticker (KC=F) and ice_stock_report_code (COFFEE-C) columns
- macros/__init__.py: added prices_glob() and ice_stocks_glob()
- pipelines.py: added extract_prices and extract_ice entries

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

transform/sqlmesh_materia/models/serving/ice_warehouse_stocks.sql

@@ -0,0 +1,78 @@
+-- Serving mart: ICE certified Coffee C warehouse stocks, analytics-ready.
+--
+-- Adds 30-day rolling average, week-over-week change, and drawdown from
+-- 52-week high. Physical supply indicator used alongside S/D and positioning.
+--
+-- "Certified stocks" = coffee graded and stamped as eligible for delivery
+-- against ICE Coffee C futures — traders watch this as a squeeze indicator.
+--
+-- Grain: one row per report_date.
+
+MODEL (
+  name serving.ice_warehouse_stocks,
+  kind INCREMENTAL_BY_TIME_RANGE (
+    time_column report_date
+  ),
+  grain (report_date),
+  start '2000-01-01',
+  cron '@daily'
+);
+
+WITH base AS (
+  SELECT
+    f.report_date,
+    f.total_certified_bags,
+    f.pending_grading_bags,
+
+    -- Week-over-week change (compare to 7 calendar days ago via LAG over ordered rows)
+    -- Using LAG(1) since data is daily: compares to previous trading/reporting day
+    f.total_certified_bags
+      - LAG(f.total_certified_bags, 1) OVER (ORDER BY f.report_date)  AS wow_change_bags,
+
+    -- 30-day rolling average (smooths daily noise)
+    round(
+      AVG(f.total_certified_bags::double) OVER (
+        ORDER BY f.report_date ROWS BETWEEN 29 PRECEDING AND CURRENT ROW
+      ),
+      0
+    )                                                                   AS avg_30d_bags,
+
+    -- 52-week high (365 calendar days ≈ 252 trading days; use 365-row window as proxy)
+    MAX(f.total_certified_bags) OVER (
+      ORDER BY f.report_date ROWS BETWEEN 364 PRECEDING AND CURRENT ROW
+    )                                                                   AS high_52w_bags,
+
+    -- Drawdown from 52-week high (pct below peak — squeeze indicator)
+    round(
+      (f.total_certified_bags::double
+       - MAX(f.total_certified_bags) OVER (
+           ORDER BY f.report_date ROWS BETWEEN 364 PRECEDING AND CURRENT ROW
+         )::double
+      )
+      / NULLIF(
+          MAX(f.total_certified_bags) OVER (
+            ORDER BY f.report_date ROWS BETWEEN 364 PRECEDING AND CURRENT ROW
+          )::double,
+          0
+        ) * 100,
+      2
+    )                                                                   AS drawdown_from_52w_high_pct
+
+  FROM foundation.fct_ice_warehouse_stocks f
+  WHERE f.report_date BETWEEN @start_ds AND @end_ds
+)
+
+SELECT
+  b.report_date,
+  d.commodity_name,
+  d.ice_stock_report_code,
+  b.total_certified_bags,
+  b.pending_grading_bags,
+  b.wow_change_bags,
+  b.avg_30d_bags,
+  b.high_52w_bags,
+  b.drawdown_from_52w_high_pct
+FROM base b
+CROSS JOIN foundation.dim_commodity d
+WHERE d.ice_stock_report_code = 'COFFEE-C'
+ORDER BY b.report_date