feat: add vim query navigation

src/main.rs

@@ -55,6 +55,8 @@ Navigation:
   Explorer and rows/schema bottom borders align; table names appear in the
   top-right border, with page/column status below. Read errors appear above the query editor.
   Query editor starts in NORMAL: i/a/I/A enters INSERT; hjkl/arrows move.
+  NORMAL also supports w/b/e (word motions), 0/^/$ (line motions), and
+  gg/G (first/last line). Words distinguish identifiers from punctuation.
   In INSERT, type SQL; Enter inserts a newline. Arrow keys, Home/End,
   Backspace/Delete, Ctrl-U (clear), and multiline pasting are supported.
   Esc leaves INSERT first; Esc in NORMAL returns to the explorer.