fix(settings): reassigning a keyboard shortcut now takes effect and updates the menu (#1357)

[datlechin]

Fixes #1357.

Reassigning some shortcuts had no effect, and the menu kept showing the old key. Execute Query (and Execute All Statements, Cancel Query) used hardcoded .keyboardShortcut modifiers that never read the custom store, so a remap was saved but never dispatched or shown. Toggle Inspector was wired correctly, but a bare key like Space cannot fire as a menu key equivalent.

Changes

• Route Execute Query (menu and toolbar), Execute All Statements, and Cancel Query through the shortcut store so a reassignment fires and shows in the menu. Made the latter two customizable actions with defaults.
• Require a modifier key for menu-dispatched actions in the recorder; bare keys are only allowed for grid actions that have a real keyDown path (Preview FK Reference, Clear Selection, Delete).
• Sanitize stored shortcuts on load so a stale bare-key override self-heals back to its default.

Tests

Added 12 tests covering the new defaults, the bare-key validation predicate, conflict detection, and load-time sanitization. All pass.