The frontend writes 'archived: true' (lowercase) via handleUpdateFrontmatter,
but the Rust parser only recognized 'Archived' (titlecase). This caused all
notes archived from within Laputa to be read back as not archived — they
continued appearing in the sidebar and note list after restart.
Fix: add alias = "archived" to the serde attribute, matching the pattern
already used for 'trashed'/'Trashed'.
Regression tests added for both lowercase and titlecase variants.
3c711cbe04