refactor: Delete legacy TRREB Python modules (#47)

- Delete portfolio_app/toronto/schemas/trreb.py
- Delete portfolio_app/toronto/parsers/trreb.py
- Delete portfolio_app/toronto/loaders/trreb.py
- Remove TRREB imports from __init__.py files

Part of Sprint 9: Toronto Neighbourhood Dashboard transition
See docs/changes/Change-Toronto-Analysis-Reviewed.md

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

portfolio_app/toronto/schemas/__init__.py

@@ -13,12 +13,8 @@ from .dimensions import (
     TimeDimension,
     TRREBDistrict,
 )
-from .trreb import TRREBMonthlyRecord, TRREBMonthlyReport
 
 __all__ = [
-    # TRREB
-    "TRREBMonthlyRecord",
-    "TRREBMonthlyReport",
     # CMHC
     "CMHCRentalRecord",
     "CMHCAnnualSurvey",

portfolio_app/toronto/schemas/trreb.py

@@ -1,52 +0,0 @@
-"""Pydantic schemas for TRREB monthly market data."""
-
-from datetime import date
-from decimal import Decimal
-
-from pydantic import BaseModel, Field
-
-
-class TRREBMonthlyRecord(BaseModel):
-    """Schema for a single TRREB monthly summary record.
-
-    Represents aggregated sales data for one district in one month.
-    """
-
-    report_date: date = Field(description="First of month (YYYY-MM-01)")
-    area_code: str = Field(
-        max_length=3, description="District code (W01, C01, E01, etc.)"
-    )
-    area_name: str = Field(max_length=100, description="District name")
-    area_type: str = Field(max_length=10, description="West / Central / East / North")
-    sales: int = Field(ge=0, description="Number of transactions")
-    dollar_volume: Decimal = Field(ge=0, description="Total sales volume ($)")
-    avg_price: Decimal = Field(ge=0, description="Average sale price ($)")
-    median_price: Decimal = Field(ge=0, description="Median sale price ($)")
-    new_listings: int = Field(ge=0, description="New listings count")
-    active_listings: int = Field(ge=0, description="Active listings at month end")
-    avg_sp_lp: Decimal = Field(
-        ge=0, le=200, description="Avg sale price / list price ratio (%)"
-    )
-    avg_dom: int = Field(ge=0, description="Average days on market")
-
-    model_config = {"str_strip_whitespace": True}
-
-
-class TRREBMonthlyReport(BaseModel):
-    """Schema for a complete TRREB monthly report.
-
-    Contains all district records for a single month.
-    """
-
-    report_date: date
-    records: list[TRREBMonthlyRecord]
-
-    @property
-    def total_sales(self) -> int:
-        """Total sales across all districts."""
-        return sum(r.sales for r in self.records)
-
-    @property
-    def district_count(self) -> int:
-        """Number of districts in report."""
-        return len(self.records)