Home: pin folders and list their newest PDFs (#383)

* Home: pin folders and list their newest PDFs

File > Pin folder to Home... (or "Pin a folder..." on Home) pins up to 8
folders. Each lists its newest PDFs with how long ago and size, opens one
with a click, and can be unpinned. Folders are read on a worker thread and
listed again every few seconds while Home shows, so new scans appear by
themselves; an unreadable folder (moved, offline synced drive) stays pinned
and says so. A folder is described by where it is ("iCloud Drive",
"OneDrive - Contoso", "Documents > Work") instead of its full path.

Cloud drives work through their local synced folder; nothing goes through a
provider API. Settings keep absolute paths only, deduplicated and capped.

Tests: crates/ui-egui/tests/folders.rs (8) and folders_ui unit tests (4).
Command label translated in every catalog; Home strings in fr, es, ja,
zh-hans and zh-hant; catalog hashes updated in ATTRIBUTION.toml.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Add my contributor name (amitabhthakur)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Home pinned folders: Russian strings; regenerate ATTRIBUTION.md

The Russian catalog (#375) landed while this branch was open: its coverage
tests need the new command label and Home strings. ATTRIBUTION.md is
regenerated (cargo xtask assets --write), which also adds the ru.tsv row
that #375 left out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

contributors/people.toml

@@ -56,3 +56,6 @@ sync_github_name = false
 real_name = "Chester Fung"
 display_name = "Chester Fung"
 sync_github_name = true
+
+[people.amitabhthakur]
+sync_github_name = true