09a07b510b
Editors' changes are now auto-saved (5 s after the last edit, at most
30 s after the first unsaved one, retried on failure) with a status
indicator; leaving the page with unsaved changes prompts a warning.
Each schedule file keeps a published snapshot next to the draft.
Viewer/cis roles load and export only the published snapshot; the
editor's draft becomes visible to them only after "Publikovat".
Toolbar shows the publish state ("Nepublikované změny" / "Publikováno
HH:MM"), the file manager shows the publish date, and viewers pick up a
new publish automatically within a minute.
Server: GET /api/files/:id?view=published, POST /api/files/:id/publish,
?view=published on all exports, one-time migration that seeds the
published snapshot from the current data on startup.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>