feat(create): add --list flag to print available templates

[DaveHanns]

Summary

Adds a --list flag to apify create so template ids can be discovered non-interactively (agent contexts, CI, non-TTY shells) without visiting the actor-templates GitHub repo or hitting the interactive picker. Combined with --json, the output is machine-parseable.

Addresses finding F34 — no non-interactive discovery path exists today for apify create --template <id>, which is the only way to invoke the command from an agent.

What changes

• src/commands/create.ts
  • New list: Flags.boolean(...) flag (no char; --list only, to avoid clashing with common short-flag conventions).
  • static override enableJsonFlag = true so the framework's built-in --json support is available on this command.
  • Two new examples in static examples (apify create --list and apify create --list --json).
  • New early-return branch at the top of run(), after the manifest fetch is kicked off but before any actor-name validation or filesystem mkdir. Reuses the same fetchManifest() mechanism the interactive picker already uses — no new dependency, no new HTTP client, no new fetch URL. Fields exposed: id (mapped from Template.name, matching what --template accepts), label, category (language), description.
  • Text form uses tab-separated output (<id>\t<language>\t<description>) so it pipes cleanly through awk / cut.

No existing behavior changes — apify create without --list is identical to before.

Test plan

• pnpm exec tsc --noEmit -p . passes (verified locally).
• pnpm exec oxlint --type-aware src/commands/create.ts passes (verified locally).
• apify create --list in a non-TTY shell prints tab-separated <id>\t<language>\t<description> lines and exits 0 without creating a directory.
• apify create --list --json prints a {"templates": [...]} JSON object with id, label, category, description fields and exits 0.
• apify create my-actor --template <id-from-list> --skip-dependency-install still works (no regression on the create path).
• apify create with no args still triggers the interactive picker (no regression on interactive path).

Notes for reviewers

• The choice to key the JSON on id: t.name (rather than Template.id) matches the string that --template accepts today; getTemplateDefinition looks up by t.name === maybeTemplateName. Exposing anything else would be confusing.
• No test file added yet — the interactive picker is not covered by unit tests either, and adding one would require mocking the manifest fetch. Happy to add a test in a follow-up if reviewers prefer.