`gh skill install android/skills` can't find skills (only exact paths work)

GitHub CLI's skill manager can't find the skills in this repo by name:

```
$ gh skill install android/skills

Using ref v1.0.0 (d9bcae65)
no skills found in android/skills
Expected skills in skills/*/SKILL.md, skills/{scope}/*/SKILL.md,
{prefix}/skills/*/SKILL.md, {prefix}/skills/{scope}/*/SKILL.md,
*/SKILL.md, or plugins/*/skills/*/SKILL.md
This repository may be a curated list rather than a skills publisher
```

The only thing that works today is the exact path.

```
$ gh skill install android/skills performance/r8-analyzer/SKILL.md
```

This is because `gh skill` only discovers skills under a `skills/` directory, while here they live under topic folders without one and two or more levels deep (e.g. `performance/r8-analyzer/SKILL.md`).

I understand the Agent Skills spec doesn't say anything about repository depth, so strictly this is a `gh skill` limitation rather than a problem with this repo (related: cli/cli#13372).
That said, having the tooling walk arbitrarily deep has real trade-offs of its own, such as longer discovery times, so I don't think it's clear-cut that `gh skill` should match every possible layout.

With that in mind, would you consider arranging the skills to fit one of the layouts `gh skill` already supports, so they can be installed/previewed by name?
For example, keeping the topic grouping and adding a `skills/` segment (`performance/skills/r8-analyzer/SKILL.md`), or collecting them under a top-level `skills/`.

I realize this repo is primarily meant to be used through the Android CLI.
In practice, though, I'd like to use these skills alongside various others, so being able to pull them in with `gh skill` too would be really convenient.

Review the current topic-folder layout, including performance/r8-analyzer/SKILL.md, and the supported paths printed by gh skill install. Reproduce the android/skills discovery failure, then verify that skills can be installed or previewed by name while topic grouping is preserved.

Written by the indexing model from the issue text.