feat: add commodity ETF ingestion universe

[C00ldudeNoonan]

Summary

• Fixes Expand ETF universe ingestion for the technical-analysis framework (follow-up to #109) #114
• Adds a 12-symbol commodity ETF MarketStack universe: GLD, SLV, USO, UNG, DBA, DBC, CORN, WEAT, SOYB, CPER, PPLT, PALL.
• Registers commodity_etfs_raw in Dagster partitions, asset, job, checks, and definitions.
• Adds stg_commodity_etfs plus source/docs/tests and includes commodity_etf in technical_price_universe.
• Includes commodity_etfs_raw in current_data_coverage and OHLC data-quality routing.
• Fixes shared weekly coverage asset-check SQL to use BigQuery-native date generation/date truncation.

Validation

• uv run ruff check .
• uv run ruff format --check .
• uv run --with duckdb pytest tests/test_schedules.py tests/test_market_checks.py -q
• uv run dg check defs
• uv run --project macro_agents dbt parse --project-dir dbt_project --profiles-dir dbt_project
• uv run --project macro_agents dbt ls --project-dir dbt_project --profiles-dir dbt_project --select stg_commodity_etfs+
• uv run --project macro_agents dbt compile --project-dir dbt_project --profiles-dir dbt_project --select stg_commodity_etfs technical_price_universe current_data_coverage
• uv run dg launch --job commodity_etfs_ingestion_job --partition "2026-07-01|GLD"
• uv run --project macro_agents dbt build --project-dir dbt_project --profiles-dir dbt_project --select stg_commodity_etfs technical_price_universe current_data_coverage

Notes

• Smoke backfill loaded only GLD for the current month; the commodity ETF coverage check executes now but warns until the full universe/history is backfilled.

[C00ldudeNoonan]

@codex please review this PR.