[SandObserver]

Summary

• Read a sequence written level with the key it belongs to as that key's value, which is how most YAML is written and what Dashy's own default config does with navLinks; a mapping at the same column stays the parent's next key. This also covers a Homepage group nested by two spaces rather than four.
• Read block scalars, folded and literal, with chomping indicators and an explicit indentation digit. The body is consumed during the scan, so a list dash, a comment marker or a tab inside it is text and never structure.
• Read [] and {} as an empty list and mapping. A flow collection with contents still refuses, since parsing that is where guessing would start.
• Add a fixture in the flush layout and cover each construct, including that the two layouts of the same document parse to the same thing.

Testing
All green: 1092 backend, 618 frontend, 94.8% line coverage, lint, format, both typechecks, paths:check and cache-busting. Checked against js-yaml on fourteen real files, ten community and official Dashy configs plus a real four-file gethomepage setup: every file both parsers accept parses identically, and the one refusal left is an Ansible template that js-yaml rejects too. Before this, eight of eleven Dashy configs and the gethomepage services file were refused outright.

Checklist

• Stays within the project constraints: one container, no runtime dependencies, no build step (see CONTRIBUTING.md).
• Tests added or updated for new logic, and the full suite, lint, and typechecks pass.
• Docs updated if behavior or configuration changed.
• CHANGELOG.md updated under Unreleased if the change is user-visible.