feat(calendar): add calendar print option

[keilogic]

Summary

• add Print Calendar actions to the calendar side menu and desktop toolbar
• print the calendar view with a scoped print mode that hides the Runbox header, calendar toolbar, side menu, and add-event controls
• add component specs for the print controls and print-mode cleanup

Tests

• npm ci
• npx tsc -p src/tsconfig.app.json --noEmit
• npx tsc -p src/tsconfig.spec.json --noEmit
• npx eslint src/app/calendar-app/calendar-app.component.ts src/app/calendar-app/calendar-app.component.spec.ts
• npx ng test --watch=false --browsers=FirefoxHeadless --include=src/app/calendar-app/calendar-app.component.spec.ts
• npm run lint -- --quiet
• npx ng test --watch=false --browsers=FirefoxHeadless
• node src/build/pre-build.js
• npx ng build --configuration production --base-href=/app/ runbox7
• node src/build/post-build.js
• git diff --check
• git diff --cached --check
• npm run policy

npm run policy exits successfully; it still prints historical upstream commit-message warnings unrelated to this PR.

AI disclosure

I used OpenAI Codex (GPT-5) to help implement and test this PR. The AI-assisted work was in the calendar component template/class/spec and the print-specific global stylesheet rules.

Closes #1057