[fix] Change keyboard event handling from event.key to event.code

This fixes keyboard shortcuts not working on non-English (non-Latin) keyboard layouts.

Changes:
- KeyComboImpl.fromEvent() now uses event.code instead of event.key
- Updated isModifier check to use key codes for modifier keys
- Added getDisplayKey() method to convert key codes to readable names
- Updated Escape key handling in keybindingService to use event.code
- Updated KeybindingPanel captureKeybinding to use event.code
- Migrated all core keybindings from event.key to event.code format
- Fixed tests to mock event.code instead of event.key

Fixes #5252

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tests-ui/tests/services/keybindingService.escape.test.ts

@@ -66,7 +66,7 @@ describe('keybindingService - Escape key handling', () => {
 
   it('should execute ExitSubgraph command when Escape is pressed', async () => {
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       bubbles: true,
       cancelable: true
     })
@@ -83,7 +83,7 @@ describe('keybindingService - Escape key handling', () => {
 
   it('should not execute command when Escape is pressed with modifiers', async () => {
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       ctrlKey: true,
       bubbles: true,
       cancelable: true
@@ -100,7 +100,7 @@ describe('keybindingService - Escape key handling', () => {
   it('should not execute command when typing in input field', async () => {
     const inputElement = document.createElement('input')
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       bubbles: true,
       cancelable: true
     })
@@ -130,7 +130,7 @@ describe('keybindingService - Escape key handling', () => {
     document.body.appendChild(dialog)
 
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       bubbles: true,
       cancelable: true
     })
@@ -158,7 +158,7 @@ describe('keybindingService - Escape key handling', () => {
     )
 
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       bubbles: true,
       cancelable: true
     })
@@ -185,7 +185,7 @@ describe('keybindingService - Escape key handling', () => {
     keybindingService = useKeybindingService()
 
     const event = new KeyboardEvent('keydown', {
-      key: 'Escape',
+      code: 'Escape',
       bubbles: true,
       cancelable: true
     })