Complete Phase 4.1 test suite updates - all 174 tests passing

Fixed all remaining test failures after Pydantic v2 migration:

Core fixes:
- Date handling: Convert date objects to ISO strings across 4 files
- Model serialization: Use model_dump(mode='json') for JSON compatibility
- Optional fields: Made time_period_months Optional[int] in models
- Dict access: Replace .get() with getattr() for dynamic attributes

Test updates:
- Updated 50+ test fixtures from dicts to Deal models
- Fixed date-based tests to use recent dates for time filtering
- Added missing imports (CoordinatePoint, MarketActivityScore, DealStatistics)
- Updated assertions from dict keys to model attributes (snake_case)

Files modified:
- nadlan_mcp/govmap/market_analysis.py
- nadlan_mcp/govmap/statistics.py
- nadlan_mcp/govmap/models.py
- nadlan_mcp/fastmcp_server.py
- tests/test_govmap_client.py
- tests/test_fastmcp_tools.py
- .cursor/plans/TEST-UPDATE-STATUS.md (comprehensive documentation)

Result: 174/174 tests passing (100%) ✅

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

nadlan_mcp/govmap/models.py

@@ -228,7 +228,7 @@ class MarketActivityScore(BaseModel):
     total_deals: int = Field(..., description="Total deals in period")
     deals_per_month: float = Field(..., description="Average deals per month")
     trend: str = Field(..., description="Market trend (increasing, stable, decreasing)")
-    time_period_months: int = Field(..., description="Analysis period in months")
+    time_period_months: Optional[int] = Field(None, description="Analysis period in months (None = all data)")
     monthly_distribution: Dict[str, int] = Field(
         default_factory=dict,
         description="Deals per month (YYYY-MM: count)"
@@ -275,7 +275,7 @@ class LiquidityMetrics(BaseModel):
     """
     liquidity_score: float = Field(..., description="Overall liquidity score (0-100)", ge=0, le=100)
     total_deals: int = Field(..., description="Total deals in period")
-    time_period_months: int = Field(..., description="Analysis period in months")
+    time_period_months: Optional[int] = Field(None, description="Analysis period in months (None = all data)")
     avg_deals_per_month: float = Field(..., description="Average deals per month")
     deal_velocity: float = Field(..., description="Deal velocity (deals per month)")
     market_activity_level: str = Field(..., description="Activity level (very_high, high, moderate, low, very_low)")