macOS: open PDFs from Finder, Open With and the Dock (#73)

Finder hands files to an app as an Apple event, not on the command
line. winit doesn't handle it, so AppKit answered "PrintCraft cannot
open files in the PDF document format". The bundle also declared no PDF
document type: its Info.plist still carried the sibling image editor's
types.

- Info.plist declares PDF (by extension and MIME type) as a document
  type, role Editor, rank Alternate: offered under Open With and
  settable as the default, without taking over on install.
- apps/printcraft registers open-documents and quit Apple event
  handlers through fmv-macos-events (=0.1.0, the audited safe wrapper
  PhotoCraft uses, since the Objective-C interop needs unsafe), before
  the launch event arrives.
- printcraft-ui-egui gains OsEvent and PrintCraftApp::os_events, polled
  every frame: Open opens each file as File > Open does; Quit closes the
  window like its close button, so unsaved changes are asked about.

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

parity/acrobat-features.toml

@@ -22,8 +22,8 @@ milestone = "M1"
 status = "shipped"
 commands = ["file.open"]
 tools = ["doc_open"]
-evidence = ["crates/automation/tests/automation.rs::open_inspect_render_and_find", "crates/ui-egui/tests/ui.rs::opening_a_pdf_shows_comments_and_bookmarks"]
-notes = ""
+evidence = ["crates/automation/tests/automation.rs::open_inspect_render_and_find", "crates/ui-egui/tests/ui.rs::opening_a_pdf_shows_comments_and_bookmarks", "crates/ui-egui/tests/ui.rs::files_and_quit_from_the_operating_system"]
+notes = "File ▸ Open, the command line (Linux and Windows file associations), and on macOS Finder, Open With and the Dock (Apple events; the bundle declares PDF as a document type)"
 
 [[feature]]
 id = "core.repair-broken-files"