fix: create action ignores size/replicas inputs

[gigatim]

Summary

• The handleCreate function (used by action: create and action: create_deploy) never read the size or replicas inputs, so they were silently ignored
• After app creation, now calls handleScale when either size or replicas is provided
• Updated action.yml input descriptions to reflect that size and replicas work with create actions
• Fixed a pre-existing type error in the test suite's mockExecWithRevParse helper
• Added tests for create-with-size and create-without-size scenarios

Test plan

• Existing tests pass (make test — 38 tests)
• New test verifies scale API is called after create when size is provided
• New test verifies scale API is NOT called after create when size is omitted
• Manual: test action: create with size: 0.5 in a workflow