Add x as alias for d (delete/cut) in visual modes

In vim, x in visual mode is equivalent to d — both delete the selection.
Add x as a secondary binding for visual_delete and visual_line_delete.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: chasleslr

sqlit/core/keymap.py

@@ -377,6 +377,7 @@ def _build_action_keys(self) -> list[ActionKeyDef]:
             ActionKeyDef("V", "switch_to_visual_line_mode", "query_visual"),
             ActionKeyDef("y", "visual_yank", "query_visual"),
             ActionKeyDef("d", "visual_delete", "query_visual"),
+            ActionKeyDef("x", "visual_delete", "query_visual", primary=False),
             ActionKeyDef("c", "visual_change", "query_visual"),
             ActionKeyDef("enter", "visual_execute", "query_visual"),
             ActionKeyDef("h", "cursor_left", "query_visual"),
@@ -407,6 +408,7 @@ def _build_action_keys(self) -> list[ActionKeyDef]:
             ActionKeyDef("v", "switch_to_visual_mode", "query_visual_line"),
             ActionKeyDef("y", "visual_line_yank", "query_visual_line"),
             ActionKeyDef("d", "visual_line_delete", "query_visual_line"),
+            ActionKeyDef("x", "visual_line_delete", "query_visual_line", primary=False),
             ActionKeyDef("c", "visual_line_change", "query_visual_line"),
             ActionKeyDef("j", "cursor_down", "query_visual_line"),
             ActionKeyDef("k", "cursor_up", "query_visual_line"),