Fix input keyboard shortcut isolation

[han4wluc]

Summary:

• Suppress Route Graphics global keyboard handling when key events originate from editable text targets.
• Stop hidden input keydown/keyup events from bubbling to document-level shortcuts while preserving normal text editing and submit behavior.
• Add unit and VT coverage for focused inputs using Space without triggering global shortcuts, then bump the package patch version to 1.20.1.

Tests:

• bunx prettier --check src/util/keyboardManager.js src/util/inputDomBridge.js spec/elements/eventSemantics.spec.js spec/util/inputDomBridge.spec.js vt/specs/input/input-keyboard-isolation.yaml package.json
• bun run test
• bun run vt:screenshot
• docker run --rm --user $(id -u):$(id -g) -e RTGL_VT_DEBUG=true -v "$PWD:/workspace" docker.io/han4wluc/rtgl:playwright-v1.57.0-rtgl-v1.1.0 rtgl vt report

VT:

• Screenshot capture completed: 186/186 succeeded.
• Report completed with 0 mismatched images.