refactor: multi-dashboard structural migration

- Rename dbt project from toronto_housing to portfolio
- Restructure dbt models into domain subdirectories:
  - shared/ for cross-domain dimensions (dim_time)
  - staging/toronto/, intermediate/toronto/, marts/toronto/
- Update SQLAlchemy models for raw_toronto schema
- Add explicit cross-schema FK relationships for FactRentals
- Namespace figure factories under figures/toronto/
- Namespace notebooks under notebooks/toronto/
- Update Makefile with domain-specific targets and env loading
- Update all documentation for multi-dashboard structure

This enables adding new dashboard projects (e.g., /football, /energy)
without structural conflicts or naming collisions.

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

dbt/models/shared/_shared.yml

@@ -0,0 +1,33 @@
+version: 2
+
+models:
+  - name: stg_dimensions__time
+    description: "Staged time dimension - shared across all projects"
+    columns:
+      - name: date_key
+        description: "Primary key (YYYYMM format)"
+        data_tests:
+          - unique
+          - not_null
+      - name: full_date
+        description: "First day of month"
+        data_tests:
+          - not_null
+      - name: year
+        description: "Calendar year"
+        data_tests:
+          - not_null
+      - name: month
+        description: "Month number (1-12)"
+        data_tests:
+          - not_null
+      - name: quarter
+        description: "Quarter (1-4)"
+        data_tests:
+          - not_null
+      - name: month_name
+        description: "Month name"
+        data_tests:
+          - not_null
+      - name: is_month_start
+        description: "Always true (monthly grain)"

dbt/models/shared/_sources.yml

@@ -0,0 +1,25 @@
+version: 2
+
+sources:
+  - name: shared
+    description: "Shared dimension tables used across all dashboards"
+    database: portfolio
+    schema: public
+    tables:
+      - name: dim_time
+        description: "Time dimension (monthly grain) - shared across all projects"
+        columns:
+          - name: date_key
+            description: "Primary key (YYYYMM format)"
+          - name: full_date
+            description: "First day of month"
+          - name: year
+            description: "Calendar year"
+          - name: month
+            description: "Month number (1-12)"
+          - name: quarter
+            description: "Quarter (1-4)"
+          - name: month_name
+            description: "Month name"
+          - name: is_month_start
+            description: "Always true (monthly grain)"

dbt/models/shared/stg_dimensions__time.sql

@@ -1,9 +1,10 @@
 -- Staged time dimension
--- Source: dim_time table
+-- Source: shared.dim_time table
 -- Grain: One row per month
+-- Note: Shared dimension used across all dashboard projects
 
 with source as (
-    select * from {{ source('toronto_housing', 'dim_time') }}
+    select * from {{ source('shared', 'dim_time') }}
 ),
 
 staged as (

dbt/models/staging/toronto/_sources.yml

@@ -1,10 +1,10 @@
 version: 2
 
 sources:
-  - name: toronto_housing
-    description: "Toronto housing data loaded from CMHC and City of Toronto sources"
+  - name: toronto
+    description: "Toronto data loaded from CMHC and City of Toronto sources"
     database: portfolio
-    schema: public
+    schema: raw_toronto
     tables:
       - name: fact_rentals
         description: "CMHC annual rental survey data by zone and bedroom type"
@@ -16,12 +16,6 @@ sources:
           - name: zone_key
             description: "Foreign key to dim_cmhc_zone"
 
-      - name: dim_time
-        description: "Time dimension (monthly grain)"
-        columns:
-          - name: date_key
-            description: "Primary key (YYYYMMDD format)"
-
       - name: dim_cmhc_zone
         description: "CMHC zone dimension with geometry"
         columns:

dbt/models/staging/toronto/_staging.yml

@@ -18,15 +18,6 @@ models:
         tests:
           - not_null
 
-  - name: stg_dimensions__time
-    description: "Staged time dimension"
-    columns:
-      - name: date_key
-        description: "Date dimension key (YYYYMMDD)"
-        tests:
-          - unique
-          - not_null
-
   - name: stg_dimensions__cmhc_zones
     description: "Staged CMHC zone dimension"
     columns:

dbt/models/staging/toronto/stg_cmhc__rentals.sql

@@ -6,8 +6,8 @@ with source as (
     select
         f.*,
         t.year as survey_year
-    from {{ source('toronto_housing', 'fact_rentals') }} f
-    join {{ source('toronto_housing', 'dim_time') }} t on f.date_key = t.date_key
+    from {{ source('toronto', 'fact_rentals') }} f
+    join {{ source('shared', 'dim_time') }} t on f.date_key = t.date_key
 ),
 
 staged as (

dbt/models/staging/toronto/stg_cmhc__zone_crosswalk.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per zone-neighbourhood intersection
 
 with source as (
-    select * from {{ source('toronto_housing', 'bridge_cmhc_neighbourhood') }}
+    select * from {{ source('toronto', 'bridge_cmhc_neighbourhood') }}
 ),
 
 staged as (

dbt/models/staging/toronto/stg_dimensions__cmhc_zones.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per zone
 
 with source as (
-    select * from {{ source('toronto_housing', 'dim_cmhc_zone') }}
+    select * from {{ source('toronto', 'dim_cmhc_zone') }}
 ),
 
 staged as (

dbt/models/staging/toronto/stg_toronto__amenities.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per neighbourhood per amenity type per year
 
 with source as (
-    select * from {{ source('toronto_housing', 'fact_amenities') }}
+    select * from {{ source('toronto', 'fact_amenities') }}
 ),
 
 staged as (

dbt/models/staging/toronto/stg_toronto__census.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per neighbourhood per census year
 
 with source as (
-    select * from {{ source('toronto_housing', 'fact_census') }}
+    select * from {{ source('toronto', 'fact_census') }}
 ),
 
 staged as (

dbt/models/staging/toronto/stg_toronto__crime.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per neighbourhood per year per crime type
 
 with source as (
-    select * from {{ source('toronto_housing', 'fact_crime') }}
+    select * from {{ source('toronto', 'fact_crime') }}
 ),
 
 staged as (

dbt/models/staging/toronto/stg_toronto__neighbourhoods.sql

@@ -3,7 +3,7 @@
 -- Grain: One row per neighbourhood (158 total)
 
 with source as (
-    select * from {{ source('toronto_housing', 'dim_neighbourhood') }}
+    select * from {{ source('toronto', 'dim_neighbourhood') }}
 ),
 
 staged as (