fix: Repair data pipeline with StatCan CMHC rental data

- Add StatCan CMHC parser to fetch rental data from Statistics Canada API
- Create year spine (2014-2025) as time dimension driver instead of census
- Add CMA-level rental and income intermediate models
- Update mart_neighbourhood_overview to use rental years as base
- Fix neighbourhood_service queries to match dbt schema
- Add CMHC data loading to pipeline script

Data now flows correctly: 158 neighbourhoods × 12 years = 1,896 records
Rent data available 2019-2025, crime data 2014-2024

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dbt/models/intermediate/int_neighbourhood__demographics.sql

@@ -17,7 +17,8 @@ demographics as (
         n.geometry,
         n.land_area_sqkm,
 
-        c.census_year,
+        -- Use census_year from census data, or fall back to dim_neighbourhood's year
+        coalesce(c.census_year, n.census_year, 2021) as census_year,
         c.population,
         c.population_density,
         c.median_household_income,