feat: keyboard and mouse shortcuts for scanner workflow

[JeanExtreme002]

Summary

Makes the scanner usable without reaching for the mouse and tightens the feedback the UI gives back, by adding keyboard/mouse shortcuts across the results and cheat tables and improving the status reporting.

Changes

Results table

• Double-click promotes a row to the cheat table, and Enter/Return promotes the currently selected rows — matching the gesture already used by the Memory Map / Modules / Pointer Scan tables.
• Reworked column resize modes: Address hugs its hex content (with a width floor so short addresses don't collapse it), while Value and Previous split the remaining width evenly.
• Empty-state hint painted over the viewport so a blank table reads as "ready and waiting" rather than broken.

Cheat table

• Delete key removes the selected rows (widget-scoped so it doesn't hijack Delete during inline cell editing).
• Double-clicking the Address or Type column — otherwise dead to double-click — opens Edit Selected.

Scanner panel

• The Value field receives focus the first time the panel appears, so you can type a target and press Enter immediately.
• Pressing Enter in a value field runs whichever scan is currently valid (First Scan before results exist, Next Scan once they do).

Status bar

• Reports final tallies on scan complete and on refine.
• The refine worker emits a final "Checked X/Y, kept Z…" tally so the count never ends on a stale mid-progress value.