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/expand_bang_minus_n.fish

@@ -0,0 +1,17 @@
+function expand_bang_minus_n
+    set -l token $argv[1]
+    if test -z "$token"; set token (commandline -t); end
+    
+    # Extract the number from the regex match
+    if string match -qr '!-(\d+)' -- "$token"
+        set -l n (string match -r '!-(\d+)' -- "$token")[2]
+        
+        if test (count $history) -ge $n
+            echo -- $history[$n]
+        else
+            echo -- $token
+        end
+    else
+        echo -- $token
+    end
+end