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>

scripts/db/init_schema.py

@@ -15,6 +15,7 @@ from pathlib import Path
 sys.path.insert(0, str(Path(__file__).parent.parent.parent))
 
 from portfolio_app.toronto.models import create_tables, get_engine  # noqa: E402
+from portfolio_app.toronto.models.dimensions import RAW_TORONTO_SCHEMA  # noqa: E402
 
 
 def main() -> int:
@@ -32,16 +33,30 @@ def main() -> int:
             result.fetchone()
         print("Database connection successful")
 
+        # Create domain-specific schemas
+        with engine.connect() as conn:
+            conn.execute(text(f"CREATE SCHEMA IF NOT EXISTS {RAW_TORONTO_SCHEMA}"))
+            conn.commit()
+        print(f"Created schema: {RAW_TORONTO_SCHEMA}")
+
         # Create all tables
         create_tables()
         print("Schema created successfully")
 
-        # List created tables
+        # List created tables by schema
         from sqlalchemy import inspect
 
         inspector = inspect(engine)
-        tables = inspector.get_table_names()
-        print(f"Created tables: {', '.join(tables)}")
+
+        # Public schema tables
+        public_tables = inspector.get_table_names(schema="public")
+        if public_tables:
+            print(f"Public schema tables: {', '.join(public_tables)}")
+
+        # raw_toronto schema tables
+        toronto_tables = inspector.get_table_names(schema=RAW_TORONTO_SCHEMA)
+        if toronto_tables:
+            print(f"{RAW_TORONTO_SCHEMA} schema tables: {', '.join(toronto_tables)}")
 
         return 0