Clarify skill navigation instructions for URL and local usage

[szabosteve]

Description

During testing, the agent received summarized skill content without the original URLs and then started guessing skill paths. This can happen when URL-fetching or summarization tools do not preserve Markdown links.

Because links are the main mechanism for moving through the skill tree, the landing page should make the navigation model explicit. For users who install skills locally, AGENTS.md should include the same guidance because the agent framework can inject it automatically.

Proposed change

Update the skills landing page and AGENTS.md to clarify how agents should navigate the skill tree:

• Read the relevant SKILL.md file directly.
• Follow the links in SKILL.md files as the navigation mechanism.
• Do not guess URL paths.
• When fetching SKILL.md files via a URL tool, preserve Markdown links exactly as written.

Expected outcome

Agents are less likely to lose navigation links, guess skill URLs, or follow invalid paths. The URL-based workflow becomes more robust through landing page guidance, while local installations are covered through AGENTS.md.

[szabosteve]

Suggested wording:

## Navigating this skill tree

Read the `SKILL.md` file for the relevant skill and follow the links in that file. These links are the navigation mechanism.

Do not guess URL paths.

When fetching `SKILL.md` files via a URL tool, preserve all Markdown links exactly as written. Do not summarize, paraphrase, or omit URLs.

Use search only as a discovery aid. Search results may be summarized and may not preserve all links.

Or something along these lines. Needs more work and validation.