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_census__toronto_cma.sql

@@ -0,0 +1,60 @@
+-- Intermediate: Toronto CMA census statistics by year
+-- Provides city-wide averages for metrics not available at neighbourhood level
+-- Used when neighbourhood-level data is unavailable (e.g., median household income)
+-- Grain: One row per year
+
+with years as (
+    select * from {{ ref('int_year_spine') }}
+),
+
+census as (
+    select * from {{ ref('stg_toronto__census') }}
+),
+
+-- Census data is only available for 2016 and 2021
+-- Map each analysis year to the appropriate census year
+year_to_census as (
+    select
+        y.year,
+        case
+            when y.year <= 2018 then 2016
+            else 2021
+        end as census_year
+    from years y
+),
+
+-- Toronto CMA median household income from Statistics Canada
+-- Source: Census Profile Table 98-316-X2021001
+-- 2016: $65,829 (from Census Profile)
+-- 2021: $84,000 (from Census Profile)
+cma_income as (
+    select 2016 as census_year, 65829 as median_household_income union all
+    select 2021 as census_year, 84000 as median_household_income
+),
+
+-- City-wide aggregates from loaded neighbourhood data
+city_aggregates as (
+    select
+        census_year,
+        sum(population) as total_population,
+        avg(population_density) as avg_population_density,
+        avg(unemployment_rate) as avg_unemployment_rate
+    from census
+    where population is not null
+    group by census_year
+),
+
+final as (
+    select
+        y.year,
+        y.census_year,
+        ci.median_household_income,
+        ca.total_population,
+        ca.avg_population_density,
+        ca.avg_unemployment_rate
+    from year_to_census y
+    left join cma_income ci on y.census_year = ci.census_year
+    left join city_aggregates ca on y.census_year = ca.census_year
+)
+
+select * from final