feat(keyboard): add vertical shortcut rows

[AsafMah]

Summary

This adds optional vertical shortcut rows that can be reached from the alphabet keyboard without permanently occupying keyboard space.

Users can enable a top row, a bottom row, or both. A mostly-vertical swipe from the top letter row opens the top shortcuts; a mostly-vertical swipe from the bottom letter row opens the bottom shortcuts. Normal tap input, long-press popups, horizontal swipes, and gesture typing stay separate.

What changed

• Adds shortcut_top and shortcut_bottom layout types.
• Adds simple, user-editable default shortcut-row layouts.
• Adds stable named key-code aliases for navigation actions so custom layouts do not need raw numeric codes.
• Adds top-row and bottom-row Gesture Typing settings, both defaulting off.
• Adds pointer handling for vertical-dominant row swipes and popup placement aligned to the source letter row.
• Documents usage and customization in docs/shortcut-rows.md.

Default rows

Top row:

Home
End
PgUp
PgDn
Tab
Esc

Bottom row:

←
↓
↑
→
W←
W→
Ins

W← and W→ move by word.

Safety notes

• The feature only starts from eligible alphabet letter rows.
• Shortcut-row swipes require vertical-dominant movement past the pointer step threshold.
• Cancel/phantom-up while a shortcut popup is open dismisses the popup without committing the highlighted shortcut.
• Both settings default to off.

Verification

Tested with:

./gradlew.bat :app:testOfflineDebugUnitTest \
  --tests "*ParserTest.shortcutRowsParseToPopupKeySpecs" \
  --no-daemon --console=plain

Result:

BUILD SUCCESSFUL

[LeanBitLab]

i implemented and tested the feature but compared to the current features for moving the cursor (touchpad mode) this doesnt look like an enhancement especially the down gesture for activating then moving cursor one at a time

[LeanBitLab]

i am currently planning to make the features useful for everyone while making the keyboard less complicated