The Apify platform expects the actor entry at .actor/src/main.py. Until
now Pry used `python -m apify_actor` via Dockerfile.apify, which works
but doesn't match the documented convention used by every other actor
on the platform.
- Add .actor/src/main.py as a thin asyncio wrapper around apify_actor.main()
- Swap Dockerfile.apify ENTRYPOINT to the new path
- Add `make actor-build` Makefile target that regenerates
.actor/input_schema.json from the ApifySchemaBuilder fluent API
(urls, max_pages, timeout, output_format, crawl)
Conflicts: none — .actor/actor.json (full version:3.0.0 schema with
input/output blocks inline) already existed from earlier work; this
commit adds the conventional entry path and a build hook that emits
the schema as a sibling file. Apify Console accepts either form.
