Beta 22: complete editor command and keyboard audit

[WebCrew]

Completes the bounded Phase 2 command/keyboard consistency audit.

• central, unit-tested shortcut resolver shared by the editor
• Delete key now matches the selection delete button, including one-step multi-selection Undo
• View → Keyboard Shortcuts shows all current fixed bindings
• modal dialogs, text input, key repeat, composition and Alt/AltGr are protected from accidental editor commands
• Ctrl+S remains global and commits an active Inspector field before saving
• records Beta 21 human acceptance and updates Beta 22 docs, version, tests and Windows release metadata

Reference review: Godot, Unity and Unreal use discoverable editor-wide and contextual shortcuts. Parlyn adopts the familiar Q/W/E/R and document commands, while keeping this foundation smaller and explicitly context-safe. Rebinding/profiles remain outside this step.

Local results: npm run check, release renderer build and git diff --check pass. The graphical Electron smoke test cannot run in this headless root Linux environment; the required Windows workflow runs it before merge.

Human Windows acceptance remains required after publication.