feat: eval prints its origin URL, type --focused, AGENT_BROWSER_HUMANIZE bogus warn

- eval now prints `eval @ <url>` to stderr (stdout stays the raw value) so an
  agent can catch tab drift — e.g. a logged-in fetch that hit the wrong origin —
  before trusting the result. Mitigates the issue #2/#3 P0 safety concern. (eval
  already returned the origin; the default output just never surfaced it.)
- `type --focused <text>`: type into the currently-focused element with no
  selector, for custom widgets that move focus to a hidden input (issue #2 P3).
- AGENT_BROWSER_HUMANIZE set to an unrecognized value now warns once (like the
  --humanize flag) instead of being silently ignored (Hermes #3).

cli/src/connection.rs

@@ -832,7 +832,19 @@ pub fn send_command(mut cmd: Value, session: &str) -> Result<Response, String> {
             obj.insert("_clickMode".to_string(), Value::String(m));
         }
         if let Ok(h) = std::env::var("AGENT_BROWSER_HUMANIZE") {
-            obj.insert("_humanize".to_string(), Value::String(h));
+            // Only forward a recognized level; warn once (like the --humanize flag
+            // does) when the env var is set to garbage, instead of silently
+            // ignoring it.
+            if crate::native::humanize::HumanizeLevel::parse(&h).is_some() {
+                obj.insert("_humanize".to_string(), Value::String(h));
+            } else {
+                static WARNED: std::sync::Once = std::sync::Once::new();
+                WARNED.call_once(|| {
+                    eprintln!(
+                        "warning: AGENT_BROWSER_HUMANIZE must be off|fast|human, got {h:?} (ignored)"
+                    );
+                });
+            }
         }
     }