Implement window.location Location object (Phase 17)
Add a proper Location object with URL property getters (href, protocol,
host, hostname, port, pathname, search, hash, origin), property setters
that trigger navigation, and methods (assign, replace, reload, toString).
- New crates/js/src/location.rs with Location object, dynamic property
resolution, setter-driven navigation queue, and comprehensive tests
- Replace window.location stub in iframe_bridge with real Location object
- Wire document.location as alias via resolve_document_get
- Hook location getters/setters into VM property resolution chain
- Initialize window object and document URL in script_loader
- Thread-local NavigationCommand queue for browser to consume
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>