Drop the dummy detail pages and the placeholder copy from the shipped pages

Problem/Motivation

The site template still ships two hand-built detail pages that stand in for content that should be entities: Event Page at /event-page and Program Page at /program-page. They cannot be listed, filtered, referenced or authored by a site builder, and they set the wrong expectation for how the template is structured.

Several shipped pages also carry lorem ipsum body copy, so a fresh install presents placeholder text to the client.

Steps to reproduce

1. Install the Horizon Aid site template.
2. Open /event-page and /program-page: single hand-built canvas pages.
3. Open /countries: the section intro and the country card text are lorem ipsum.

Proposed resolution

• Remove the Event Page and Program Page canvas pages, and any menu link that pointed at them. Events and programmes are handled as content, in their own issues.
• Replace the lorem ipsum body copy on the shipped pages with real Horizon Aid text.
• Keep the placeholder examples that belong to the Canvas component definitions: those are what an editor sees when a component is dropped on a page.

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes
• ❌ Release

User interface changes

• /event-page and /program-page no longer exist.
• The shipped pages read with real copy instead of lorem ipsum.

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• Removed the Event Page and Program Page placeholder pages and replaced the lorem ipsum copy on the shipped pages.