refactor(dbt): migrate to domain-scoped schema names

- Create generate_schema_name macro to use custom schema names directly
- Update dbt_project.yml schemas: staging→stg_toronto, intermediate→int_toronto, marts→mart_toronto
- Add dbt/macros/toronto/ directory for future domain-specific macros
- Fix documentation drift in PROJECT_REFERENCE.md (load-data-only→load-toronto-only)
- Update DATABASE_SCHEMA.md with new schema names
- Update CLAUDE.md database schemas table
- Update adding-dashboard.md runbook with domain-scoped pattern

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

docs/DATABASE_SCHEMA.md

@@ -122,9 +122,9 @@ erDiagram
 |--------|---------|------------|
 | `public` | Shared dimensions (dim_time) | SQLAlchemy |
 | `raw_toronto` | Toronto dimension and fact tables | SQLAlchemy |
-| `staging` | Staging models | dbt |
-| `intermediate` | Intermediate models | dbt |
-| `marts` | Analytical tables | dbt |
+| `stg_toronto` | Toronto staging models | dbt |
+| `int_toronto` | Toronto intermediate models | dbt |
+| `mart_toronto` | Toronto analytical tables | dbt |
 
 ### Raw Toronto Schema (raw_toronto)
 
@@ -149,7 +149,7 @@ Shared dimensions used across all projects:
 |-------|-------------|
 | `dim_time` | Time dimension (monthly grain) |
 
-### Staging Schema (dbt)
+### Staging Schema - stg_toronto (dbt)
 
 Staging models provide 1:1 cleaned representations of source data:
 
@@ -164,7 +164,7 @@ Staging models provide 1:1 cleaned representations of source data:
 | `stg_dimensions__cmhc_zones` | raw.cmhc_zones | CMHC zone boundaries |
 | `stg_cmhc__zone_crosswalk` | raw.crosswalk | Zone-neighbourhood mapping |
 
-### Marts Schema (dbt)
+### Marts Schema - mart_toronto (dbt)
 
 Analytical tables ready for dashboard consumption: