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/dialogs/confirm-dialog.ts

@@ -1,6 +1,7 @@
 import { Component, ElementRef, afterNextRender, inject, input, viewChild } from '@angular/core';
 import { I18nService } from '@core/i18n.service';
 import { DialogsService, type ConfirmRequest } from '@core/dialogs.service';
+import { cycleFocus } from '@core/focus-cycle';
 import { FocusService } from '@core/focus.service';
 
 @Component({
@@ -8,9 +9,12 @@ import { FocusService } from '@core/focus.service';
   template: `
     <div class="fixed inset-0 z-40 grid place-items-center bg-black/40" (mousedown)="cancel()">
       <div
+        role="dialog"
+        aria-modal="true"
+        [attr.aria-label]="request().title"
         class="w-96 border border-border bg-card p-4 text-card-foreground shadow-xl"
         (mousedown)="$event.stopPropagation()"
-        (keydown.escape)="cancel()"
+        (keydown)="onKeydown($event)"
       >
         <h2 class="text-sm font-semibold">{{ request().title }}</h2>
         <p class="mt-2 text-xs text-muted-foreground">{{ request().body }}</p>
@@ -49,6 +53,17 @@ export class ConfirmDialog {
     afterNextRender(() => this.confirmBtn().nativeElement.focus());
   }
 
+  /** Esc cancels (and stops here — see PromptDialog); Tab stays inside. */
+  onKeydown(event: KeyboardEvent): void {
+    if (event.key === 'Escape') {
+      event.preventDefault();
+      event.stopPropagation();
+      this.cancel();
+    } else {
+      cycleFocus(event.currentTarget as Element, event);
+    }
+  }
+
   submit(): void {
     const req = this.request();
     this.close();