feat(init): handle the mobile template kind in init and verify

[Bccorb]

Context

seamless-templates is adding a third template kind, mobile, alongside web and
api. The CLI branches on kind in several places and will silently ignore or
mishandle a mobile entry until it is taught about it.

Known branch points:

• src/commands/init.ts resolves alias preselection by kind === "web" and
  kind === "api", and picks a targetDir the same way.
• src/commands/verify.ts filters to kind === "web" when choosing what to exercise.

Scope

• Handle mobile wherever web and api are branched on today, including a sensible
  targetDir.
• Decide what verify does with a mobile template. Exercising it needs a simulator or
  emulator, so an explicit skip with a clear message is likely better than a silent one.
• Keep the registry and manifest schema handling in step with the templates repo.

Acceptance

• A kind: "mobile" registry entry is selectable and placed correctly.
• verify either exercises it or states plainly that it is skipping, rather than
  filtering it out silently.
• Coordinated with the templates repo issues tracked in the epic.

[Bccorb]

Part of the React Native mobile template epic: fells-code/seamless-templates#40