Apply after-selection preferences in the keyboard and mouse panel

[enaboapps]

Closes #931

Part of #935. Stacked on #936; review that first.

Change

The keyboard and the mouse panel now follow the two after-selection preferences.

Preference	Value	Behaviour after a key, suggestion or mouse action
Start from	Standard or Beginning	First row, as before
Start from	Selection	The same row and item
Next scan	Standard or Automatic	Moves after one full interval, as before
Next scan	Wait	Waits for Select, then continues from the chosen place

• With Selection, arriving suggestions do not pull the highlight to the suggestion row.
• A repeating move or scroll stopped by a switch follows the same preferences.
• Wait has no effect when automatic scanning is off.
• Unchanged: page, dock and position keys, modifier keys, leaving the panel, failures, and a pause from the pass limit. These start from the first row. So does a chosen suggestion, because its row is replaced.
• A repeat ended by a screen change or by turning repeat off starts from the first row, since no switch was pressed.
• The keyboard still tracks its wait in its own flag, separate from the shared scanner's.
• One change under default preferences: a display being added or removed no longer restarts the mouse panel's Movement page, whose keys do not depend on displays. The highlight, a pause and a failure message now stay as they were.
• A saved wait after typing keeps working through the resolved preference. PointSettings no longer carries the separate flag.

There is no settings UI yet, so users see no change until #933. No persisted schema or protocol change in this PR.

Validation at 04fb0a3

All run locally on Windows and passing:

• npm run lint, npm test, npm run build
• cargo fmt --check
• cargo clippy --all-targets -- -D warnings
• cargo test: 594 passed

New tests use the scanners directly and inject no input. Not verified in the running app.

🤖 Generated with Claude Code