fix(chrome): correct PressKey mappings to chromedp/kb constants

Old keyMap had "home":"\x00" (NUL byte) and arrow keys mapped to
random punctuation runes (\x25-\x28 = % & ' () instead of arrow
keys. "escape" was missing entirely while the V8 runtime emits it.

Drop back/home (no browser navigation semantics) and route the
remaining keys through chromedp/kb constants so they actually
dispatch as the named keys.

internal/driver/chrome/driver.go

@@ -13,6 +13,7 @@ import (
 	"github.com/chromedp/cdproto/page"
 	"github.com/chromedp/cdproto/runtime"
 	"github.com/chromedp/chromedp"
+	"github.com/chromedp/chromedp/kb"
 
 	"github.com/priyanshujain/sanderling/internal/driver"
 )
@@ -191,15 +192,17 @@ func (d *Driver) PressKey(_ context.Context, key string) error {
 	return chromedp.Run(d.tabCtx, chromedp.KeyEvent(k))
 }
 
+// keyMap covers the keys web specs may emit (enter/tab/escape/arrows).
+// "back"/"home" are intentionally absent: backspace/NUL have no navigation
+// semantics in a browser, and the V8 action mix already excludes them.
 var keyMap = map[string]string{
-	"back":  "\b",
+	"enter":  kb.Enter,
-	"home":  "\x00",
+	"tab":    kb.Tab,
-	"enter": "\r",
+	"escape": kb.Escape,
-	"tab":   "\t",
+	"up":     kb.ArrowUp,
-	"up":    "\x26",
+	"down":   kb.ArrowDown,
-	"down":  "\x28",
+	"left":   kb.ArrowLeft,
-	"left":  "\x25",
+	"right":  kb.ArrowRight,
-	"right": "\x27",
 }
 
 func (d *Driver) Hierarchy(_ context.Context) (string, error) {