implement avoid_highways and avoid_tolls on route planner

[andresilveirah]

Summary

• Add avoid_highways and avoid_tolls options to route planner and related route tools.
• Fix CLI exec output truncation that broke large static-map JSON responses.

Changes

File	Change
src/services/RoutesService.ts	Add Google Routes API routeModifiers support for avoidTolls and avoidHighways; reject non-driving use with clear error
src/services/PlacesSearcher.ts	Thread new avoid options through directions, distance matrix, and plan route flows
src/tools/maps/directions.ts	Add avoid_tolls and avoid_highways to MCP input schema
src/tools/maps/distanceMatrix.ts	Add avoid_tolls and avoid_highways to MCP input schema
src/tools/maps/planRoute.ts	Add avoid_tolls and avoid_highways to MCP input schema
src/cli.ts	Pass new route options in exec mode; replace immediate process.exit() after stdout write to avoid truncating large responses
tests/smoke.test.ts	Assert new schema fields; add non-driving modifier error check; skip live photo test without API key; raise exec buffer for large static-map output
README.md	Document new drive-only avoid options on routing tools
skills/google-maps/SKILL.md	Update tool descriptions/examples for avoid options
skills/google-maps/references/tools-api.md	Document new params for directions, distance matrix, and plan route

Test plan

• npm run build succeeds
• npm run lint — 0 errors
• npm test — all pass
• Manual verification (if applicable)

Changelog entry

- Add drive-only `avoid_tolls` and `avoid_highways` options to directions, distance matrix, and route planning tools;
- fix CLI exec output truncation for large responses like static maps;