feat(shell): add bash-style history expansions and interactive keybindings

- Replicate bash bang-operations (!^, !*, !string, etc.) via abbreviations
- Add Ctrl+G for previous path head insertion
- Add Ctrl+F for interactive history substitution
- Add Ctrl+Alt+U to quickly replace command tokens
- Update README documentation for all new features

functions/__interactive_history_sub.fish

@@ -0,0 +1,17 @@
+function __interactive_history_sub
+    set -l current_line (commandline -b)
+    set -l last_cmd $history[1]
+    
+    if string match -qr '(.+)/(.+)' -- "$current_line"
+        set -l parts (string split '/' -- "$current_line")
+        set -l old $parts[1]
+        set -l new $parts[2]
+        set -l expanded (string replace -a -- "$old" "$new" "$last_cmd")
+        commandline -r "$expanded"
+    else
+        if test -z "$current_line"
+            commandline -r "sudo $last_cmd"
+        end
+    end
+    commandline -f repaint
+end