Apply dbt project evaluator improvements

[C00ldudeNoonan]

Summary

• Adds dbt_project_evaluator with evaluator models disabled by default behind enable_dbt_project_evaluator.
• Adds safe source freshness configs aligned to Dagster-written timestamp fields.
• Adds docs/tests for previously uncovered models.
• Renames enabled misspelled/non-prefixed models to major_indices_*, stg_corporate_actions, and stg_split_adjusted_prices, with legacy wrappers disabled by default.
• Splits cross_asset_divergences into smaller intermediate components and adds as_of_date for stable comparison windows.
• Adds fetched_at to Dagster housing_inventory_raw output for future freshness support.

Validation

• dbt parse: passed
• dbt compile: passed
• dbt lint --changed: passed
• uv run ruff check src/macro_agents/defs/domains/housing.py: passed
• Validation agent: SQL validation, lint, run, tests, downstream validation passed

Notes

• stg_corporate_actions and stg_split_adjusted_prices are row-identical to legacy prod relations.
• major_indices_* differences are due dev source freshness through 2026-07-02 while prod stops 2026-05-28.
• Cross-asset date-window drift is addressed with optional as_of_date.

[C00ldudeNoonan]

@codex please review this PR.