feat: add linewise Visual selection and paste

src/main.rs

@@ -22,13 +22,13 @@ Normal: i/a insert, I/A insert at first nonblank/end, o/O new line
         Normal/Visual: prefix motions with counts (5j, 2w, 3n); Esc cancels count
         u undo, U redo, : command, / search, n/N next/previous match
         Normal/Visual: . repeats last native edit at current targets (one undo group)
-        v select, p/P paste fragments, Ctrl+k/Ctrl+e clone above/below
+        v characterwise select, V linewise select, p/P paste fragments, Ctrl+k/Ctrl+e clone above/below
         y/d/c/p/P use the system clipboard by default; config.clipboard_mode = \"separate\" isolates it
         Esc keeps only the primary caret
 Visual: motions extend selections, y copy, d/x/Delete cut, c change
         I/A insert at each selected line's first nonblank/end
         Ctrl+l split rows, Ctrl+n add occurrence, Ctrl+s skip, Ctrl+a all
-        v/Esc returns to Normal retaining carets
+        v/V switches selection shape; same selector or Esc cancels retaining carets
 Insert: Esc returns to Normal retaining carets
 Search: Enter finds next literal match, Esc cancels (case-sensitive, wraps)
 Commands: :w [PATH], :q, :q!, :wq [PATH], :plugins, :PLUGIN [ARGS]