Add MCP tools for site cloning and Blueprints

[claytoncollie]

Problem

Local supports cloning sites and creating sites from Blueprints (saved templates). For agent workflows this is valuable in two ways:

1. Safer mutations — "clone the site, mutate the clone, leave the original alone" is the cheapest path to safer agent behavior on risky changes.
2. Standardized scaffolding — teams can publish a Blueprint with their must-use plugins, theme baseline, and CI configs so new engagements start from a known-good state.

Neither is currently exposed.

Proposal

• clone_site(sourceId?, newName, newDomain?) → returns the new site's ID
• list_blueprints() → available Blueprints with name and metadata
• create_site_from_blueprint(blueprintName, siteName, domain?) → returns the new site's ID

LocalApi additions

LocalApi.cloneSite, listBlueprints, createSiteFromBlueprint.

Acceptance criteria

• Cloned sites get a unique domain by default (suffix, e.g. -clone-1) if not specified
• Blueprint creation respects all Blueprint settings (PHP version, plugins, etc.)
• New sites are immediately usable — can be started, queried, etc. via existing tools