C14.14: export HTML, HTML and folder, PDF (MuPDF story in the PDF worker) and plain text; print; rich copy

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/ely-mark/src/main.rs

@@ -6,10 +6,12 @@ mod autosave;
 mod compare;
 mod desk;
 mod engine;
+mod export;
 mod finding;
 mod folder;
 mod keys;
 mod look;
+mod output;
 mod outside;
 mod places;
 mod rename;