shell: jump cursor to line end on bash history search

history-search-* leaves the cursor at the prefix boundary, not the end,
unlike zsh's history-search-end widget. Bind the search functions to
throwaway keys and map the arrows to a macro that runs the search then
end-of-line, so prefix recall lands the cursor at EOL like zsh.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shell/.config/readline/inputrc

@@ -6,8 +6,15 @@
 $include /etc/inputrc
 
 # zsh-style prefix history search: type a prefix, Up/Down walk matching
-# history entries with cursor at end of line. Empty prefix = previous/next.
-"\e[A": history-search-backward
-"\e[B": history-search-forward
-"\eOA": history-search-backward
-"\eOB": history-search-forward
+# history entries with cursor at END of line. Empty prefix = previous/next.
+#
+# Readline's history-search-* leaves the cursor at the prefix boundary, not the
+# end (that's why zsh needs its history-search-end widget). There's no built-in
+# "search then go to end", so: bind the real functions to throwaway keys, then
+# bind the arrows to a MACRO that runs the search and then end-of-line (\C-e).
+"\C-x\C-p": history-search-backward
+"\C-x\C-n": history-search-forward
+"\e[A": "\C-x\C-p\C-e"
+"\e[B": "\C-x\C-n\C-e"
+"\eOA": "\C-x\C-p\C-e"
+"\eOB": "\C-x\C-n\C-e"