ICE extraction overhaul: API discovery + aging report + historical backfill

- Replace brittle ICE_STOCKS_URL env var with API-based URL discovery via
  the private ICE Report Center JSON API (no auth required)
- Add rolling CSV → XLS fallback in extract_ice_stocks() using
  find_latest_report() from ice_api.py
- Add ice_api.py: fetch_report_listings(), find_latest_report() with
  pagination up to MAX_API_PAGES
- Add xls_parse.py: detect_file_format() (magic bytes), xls_to_rows()
  using xlrd for OLE2/BIFF XLS files
- Add extract_ice_aging(): monthly certified stock aging report by
  age bucket × port → ice_aging/ landing dir
- Add extract_ice_historical(): 30-year EOM by-port stocks from static
  ICE URL → ice_stocks_by_port/ landing dir
- Add xlrd>=2.0.1 (parse XLS), xlwt>=1.3.0 (dev, test fixtures)
- Add SQLMesh raw + foundation models for both new datasets
- Add ice_aging_glob(), ice_stocks_by_port_glob() macros
- Add extract_ice_aging + extract_ice_historical pipeline entries
- Add 12 unit tests (format detection, XLS roundtrip, API mock, CSV output)

Seed files (data/landing/ice_aging/seed/ and ice_stocks_by_port/seed/)
must be created locally — data/ is gitignored.

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

transform/sqlmesh_materia/models/foundation/fct_ice_aging_stocks.sql

@@ -0,0 +1,58 @@
+-- Foundation fact: ICE certified Coffee C (Arabica) aging report.
+--
+-- Casts raw varchar columns to proper types and deduplicates via hash key.
+-- Grain: one row per (report_date, age_bucket).
+-- Age buckets represent how long coffee has been in certified storage.
+-- Port columns are in bags (60kg).
+
+MODEL (
+  name foundation.fct_ice_aging_stocks,
+  kind INCREMENTAL_BY_TIME_RANGE (
+    time_column report_date
+  ),
+  grain (report_date, age_bucket),
+  start '2020-01-01',
+  cron '@daily'
+);
+
+WITH cast_and_clean AS (
+  SELECT
+    TRY_CAST(report_date AS date)            AS report_date,
+    age_bucket,
+    TRY_CAST(antwerp_bags AS bigint)         AS antwerp_bags,
+    TRY_CAST(hamburg_bremen_bags AS bigint)  AS hamburg_bremen_bags,
+    TRY_CAST(houston_bags AS bigint)         AS houston_bags,
+    TRY_CAST(miami_bags AS bigint)           AS miami_bags,
+    TRY_CAST(new_orleans_bags AS bigint)     AS new_orleans_bags,
+    TRY_CAST(new_york_bags AS bigint)        AS new_york_bags,
+    TRY_CAST(total_bags AS bigint)           AS total_bags,
+
+    filename                                 AS source_file,
+
+    hash(report_date, age_bucket, total_bags) AS hkey
+  FROM raw.ice_aging_stocks
+  WHERE TRY_CAST(report_date AS date) IS NOT NULL
+    AND age_bucket IS NOT NULL
+    AND age_bucket != ''
+),
+
+deduplicated AS (
+  SELECT
+    any_value(report_date)          AS report_date,
+    any_value(age_bucket)           AS age_bucket,
+    any_value(antwerp_bags)         AS antwerp_bags,
+    any_value(hamburg_bremen_bags)  AS hamburg_bremen_bags,
+    any_value(houston_bags)         AS houston_bags,
+    any_value(miami_bags)           AS miami_bags,
+    any_value(new_orleans_bags)     AS new_orleans_bags,
+    any_value(new_york_bags)        AS new_york_bags,
+    any_value(total_bags)           AS total_bags,
+    any_value(source_file)          AS source_file,
+    hkey
+  FROM cast_and_clean
+  GROUP BY hkey
+)
+
+SELECT *
+FROM deduplicated
+WHERE report_date BETWEEN @start_ds AND @end_ds

transform/sqlmesh_materia/models/foundation/fct_ice_warehouse_stocks_by_port.sql

@@ -0,0 +1,60 @@
+-- Foundation fact: ICE historical end-of-month Coffee C certified warehouse stocks by port.
+--
+-- Covers November 1996 to present (30-year history). Casts raw varchar columns
+-- to proper types and deduplicates via hash key.
+--
+-- Grain: one row per report_date (end-of-month).
+-- Port columns are in bags (60kg).
+
+MODEL (
+  name foundation.fct_ice_warehouse_stocks_by_port,
+  kind INCREMENTAL_BY_TIME_RANGE (
+    time_column report_date
+  ),
+  grain (report_date),
+  start '1996-11-01',
+  cron '@daily'
+);
+
+WITH cast_and_clean AS (
+  SELECT
+    TRY_CAST(report_date AS date)            AS report_date,
+    TRY_CAST(new_york_bags AS bigint)        AS new_york_bags,
+    TRY_CAST(new_orleans_bags AS bigint)     AS new_orleans_bags,
+    TRY_CAST(houston_bags AS bigint)         AS houston_bags,
+    TRY_CAST(miami_bags AS bigint)           AS miami_bags,
+    TRY_CAST(antwerp_bags AS bigint)         AS antwerp_bags,
+    TRY_CAST(hamburg_bremen_bags AS bigint)  AS hamburg_bremen_bags,
+    TRY_CAST(barcelona_bags AS bigint)       AS barcelona_bags,
+    TRY_CAST(virginia_bags AS bigint)        AS virginia_bags,
+    TRY_CAST(total_bags AS bigint)           AS total_bags,
+
+    filename                                 AS source_file,
+
+    hash(report_date, total_bags)            AS hkey
+  FROM raw.ice_warehouse_stocks_by_port
+  WHERE TRY_CAST(report_date AS date) IS NOT NULL
+    AND TRY_CAST(total_bags AS bigint) IS NOT NULL
+),
+
+deduplicated AS (
+  SELECT
+    any_value(report_date)          AS report_date,
+    any_value(new_york_bags)        AS new_york_bags,
+    any_value(new_orleans_bags)     AS new_orleans_bags,
+    any_value(houston_bags)         AS houston_bags,
+    any_value(miami_bags)           AS miami_bags,
+    any_value(antwerp_bags)         AS antwerp_bags,
+    any_value(hamburg_bremen_bags)  AS hamburg_bremen_bags,
+    any_value(barcelona_bags)       AS barcelona_bags,
+    any_value(virginia_bags)        AS virginia_bags,
+    any_value(total_bags)           AS total_bags,
+    any_value(source_file)          AS source_file,
+    hkey
+  FROM cast_and_clean
+  GROUP BY hkey
+)
+
+SELECT *
+FROM deduplicated
+WHERE report_date BETWEEN @start_ds AND @end_ds