A vision pull shows the direction it will write, and Settings marks which part follows the vision and which is the owner's #5835

Part of #655: nothing changes the crew's direction without being seen first.

Done when:

• [ ] A vision pull's page shows the direction block as it will read after the merge, beside today's block.
• [ ] The repository settings page draws the direction with the fenced block marked follows docs/VISION.md, and the rest marked as the owner's.
• [ ] Looks at phone and desktop widths show both.
• [ ] Tests check both renderings, and that the shown block equals what the merge writes.