feat(workflows): add keyboard shortcut binding

[equence]

Summary

• Add a workflow shortcut binding command from the workflow tree and workflow manager.
• Use VS Code's native Define Keybinding popup to capture keyboard shortcuts.
• Rewrite the native keybinding template into the workflow run command with the selected workflow id.
• Add JSONC utilities and unit tests for workflow keybinding updates.
• Document workflow shortcut binding behavior and the user/Profile keybindings storage limitation.

Validation

• yarn run compile
• yarn run lint
• yarn run test:unit -- --grep workflowKeybindingUtils
• yarn run test:unit
• pnpm run docs:build