Standardize Site class naming

[jakekara]

Refactor: Standardize Site class naming across platforms

Summary

Rename all platform Site classes to use descriptive names (e.g., CivicPlusSite) at the source, eliminating the need for aliasing in __init__.py files.

Problem

Some platforms define descriptive class names at the source, others use a generic Site and alias in __init__.py:

Platform	Class Name in site.py	Alias in __init__.py
Civic Plus	Site ❌	CivicPlusSite
Legistar	Site ❌	LegistarSite
Digital Tow Path	DigitalTowPathSite ✅	—
Granicus	GranicusSite ✅	—
Civic Clerk	CivicClerkSite ✅	—
PrimeGov	PrimeGovSite ✅	—

Issues

1. Inconsistent patterns — Hard to grep for class definitions
2. Indirect imports — Aliasing in __init__.py adds indirection

Proposed Changes

1. Rename Site → CivicPlusSite in civic_scraper/platforms/civic_plus/site.py
2. Rename Site → LegistarSite in civic_scraper/platforms/legistar/site.py
3. Update __init__.py files to use direct imports (remove aliasing)
4. Update any imports in runner.py and tests

Files to Modify

• civic_scraper/platforms/civic_plus/site.py
• civic_scraper/platforms/civic_plus/__init__.py
• civic_scraper/platforms/legistar/site.py
• civic_scraper/platforms/legistar/__init__.py
• civic_scraper/platforms/digital_tow_path/site.py
• civic_scraper/platforms/digital_tow_path/__init__.py
• civic_scraper/runner.py
• Related tests

Acceptance Criteria

• All platform Site classes have descriptive names at the source
• No __init__.py aliasing needed for Site classes
• All imports updated throughout codebase
• All existing tests pass
• No breaking changes to public API (external imports still work via __init__.py re-exports)