Skip a YAML Block Scalar When the Prose Gate Reads a Compose File's Volume Entries #3694

Raised by the review of promotion #3693, on the change #3685 made.

container_paths in .github/actions/prose-gate/prose_lint.py decides which lines of a Compose file are a volume entry's container side by indentation alone. It does not know a YAML block scalar (| or >), so a volumes: key and a mount-shaped list item written inside one read as a real volume entry, and the home-path rule skips them.

Constructed case, checked on develop at 431ffaf:

services:
  app:
    x-readme: |
      volumes:
        - cache:/home/zed/data

In compose.yml this produces no finding. The same text in ledger.yml produces home-path. A x-note: | scalar inside a long-syntax volume entry holding - ./old:/home/zed/media is skipped the same way.

Reach is narrow: it needs mount-shaped text inside a block scalar in a Compose file, and it only hides text shaped exactly like a mount target. The smallest fix is to treat a key line ending in a block-scalar indicator as opening an opaque region, skipping every deeper-indented line until the indentation returns.