Spike: feasibility of distributing new plugins via 3rd-party official stores

## Context
> Our `azure` plugin is added into the Claude Code official plugin store... It's not easy to add a plugin to a 3rd party official plugin store. We probably won't be able to convince Anthropic to add our new plugins to their official plugin store in a timely manner.

## Scope
- Investigate the process/effort to add new (non-core) plugins to 3rd-party official stores (e.g. Claude Code).
- Recommend whether/when to pursue.

## Acceptance criteria
- Written findings + recommendation. Low priority per design.

Review the context about the existing azure plugin in the Claude Code official plugin store, then investigate the process and effort required for adding non-core plugins to third-party official stores. Document the findings and a recommendation about whether and when to pursue this, using the stated acceptance criteria as the definition of done.

Written by the indexing model from the issue text.