Put every shortcut on one shared keymap and make the app keyboard-reachable

The keymap was scattered over ShortcutsService if-chains, the file panel's
key switch, macOS-only menu accelerators and hand-typed hints in 16
tooltips x 7 locales, and large parts of the app had no keyboard path at
all. src/shared/keymap.ts is now the one table: scopes, per-platform
defaults, exact matching, formatting with localized key names, conflicts,
reserved combos and native-menu accelerators, proven by keymap.spec.ts.

- ShortcutsService resolves against the effective keymap: claim() takes
  the key (preventDefault, held keys repeat only movement, never mid-IME),
  and from a text field only chords and F-keys fire. The file panel, App,
  editor, manager and Settings windows all dispatch through it.
- FileActionsService.run is the one file-command dispatcher for the list
  keys, the row menu, the macOS menu bar and the toolbar.
- New keys: the row menu (Shift+F10 / Menu / Ctrl+Return), the source
  picker (Mod+K), the path bar (Mod+L), transfers (Mod+J), sorting
  (Alt+1-7), Shift+movement selection, close other tabs, move and
  disconnect tabs, refresh and edit on Windows/Linux, permissions, copy
  path, reveal, trash, open in default app, editor find next/previous.
- Right-click menus: soft shortcut hints, icons on the everyday verbs
  (the toolbar's glyphs), section headers, scrolling, item keys while
  open, a highlighted first item when opened from the keyboard. The panel
  source picker now renders through the same menu.
- Dialogs: role=dialog, a Tab trap via cycleFocus (WKWebView skips
  buttons on Tab without Keyboard navigation), initial focus, Esc that
  stops propagating; the chmod dialog takes focus and applies on Enter.
- Fixed: Ctrl+Tab also flipped the active panel; Esc in a manager dialog
  closed the manager; Ctrl-F/T fired Cmd shortcuts on macOS; shortcuts
  fired under dialogs; keys died after any button click on macOS; the
  editor's save prompt and find box never got focus; WebView2 reload keys;
  a window could save default settings before its first load.
- Settings closes on its own close-window key (new settingsClose request).

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

ui/src/app/skins/shadlike/app.html

@@ -31,6 +31,7 @@
         <ng-icon name="tdesignServer" size="1.25rem" class="text-muted-foreground" />
         <p class="mt-1.5 text-xs text-muted-foreground">{{ i18n.t('app.managerOpen') }}</p>
         <button
+          (click)="focusManager()"
           class="mt-3 bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90"
         >
           {{ i18n.t('app.showConnections') }}