Modernize to pyproject.toml and fix test assertion

- Remove requirements.txt and requirements-dev.txt (duplicates pyproject.toml)
- Update Dockerfile to use 'pip install .' instead of requirements.txt
- Update README.md and GitHub workflows to use 'pip install -e .[dev]'
- Fix test_get_valuation_comparables: check for 'deal_date' instead of non-existent 'asset_room_num'
  (rooms field is optional and excluded when None due to exclude_none=True)
- Fix fastmcp version constraint in pyproject.toml (>=2.13.0,<3.0.0)
- Add vcrpy to dev dependencies

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

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

.github/workflows/test.yml

@@ -20,7 +20,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -r requirements-dev.txt
+        pip install -e .[dev]
 
     - name: Run unit tests with coverage
       run: |
@@ -57,7 +57,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -r requirements-dev.txt
+        pip install -e .[dev]
 
     - name: Run black (check only)
       run: |