fix(browser): derive batch navigation outcome from command rows

A batch whose open succeeded but whose later command failed was recorded
as a failed navigation, so a following observation was wrongly labelled
stale. Use the per-command rows; when the outcome cannot be determined,
treat the page as unknown instead of claiming either result.

src/agent_tools/web_tools.py

@@ -2757,6 +2757,33 @@ class PrivateBrowserTool:
         header = "\n".join(part for part in (title, url) if part)
         return {"ok": True, "url": url, "text": f"{header}\n\n{text}".strip()}
 
+    @staticmethod
+    def _batch_navigation_outcome(output: str, command_ok: bool) -> tuple[str, str]:
+        """Outcome of a batch's last navigation: ``ok``, ``failed`` or ``unknown``.
+
+        A later command failing does not undo a navigation that succeeded,
+        so the per-command rows decide, not the batch exit status.
+        """
+
+        try:
+            rows = json.loads(output)
+        except (ValueError, TypeError):
+            rows = None
+        if isinstance(rows, list):
+            for row in reversed(rows):
+                command = row.get("command") if isinstance(row, dict) else None
+                if not (
+                    isinstance(command, list)
+                    and command
+                    and str(command[0]).lower() in {"open", "goto", "navigate"}
+                ):
+                    continue
+                if row.get("success") is True:
+                    result = row.get("result") if isinstance(row.get("result"), dict) else {}
+                    return "ok", str(result.get("url") or "")
+                return "failed", ""
+        return ("ok", "") if command_ok else ("unknown", "")
+
     @staticmethod
     def _navigated_url(output: str) -> str:
         """Final URL reported by ``open`` (after redirects), when present."""
@@ -3028,12 +3055,20 @@ class PrivateBrowserTool:
                 "untrusted_content": True,
             }
         if navigation_url:
-            if command_ok:
+            outcome, final_url = "ok" if command_ok else "failed", ""
+            if action == "batch":
+                outcome, final_url = self._batch_navigation_outcome(out, command_ok)
+            if outcome == "ok":
                 browser.navigated(
-                    (read_page or {}).get("url") or self._navigated_url(out) or navigation_url
+                    final_url
+                    or (read_page or {}).get("url")
+                    or self._navigated_url(out)
+                    or navigation_url
                 )
-            else:
+            elif outcome == "failed":
                 browser.navigation_failed(navigation_url)
+            else:
+                browser.navigation_unknown(navigation_url)
         if read_page is not None:
             if not command_ok:
                 return {

src/browser_lifecycle.py

@@ -300,6 +300,7 @@ class BrowserSession:
     navigation_generation: int = 0
     page_url: str = ""
     failed_navigation_url: str = ""
+    navigation_outcome_unknown: bool = False
     _lock: asyncio.Lock | None = field(default=None, repr=False)
     _lock_loop: Any = field(default=None, repr=False)
 
@@ -321,22 +322,39 @@ class BrowserSession:
         self.navigation_generation += 1
         self.page_url = url
         self.failed_navigation_url = ""
+        self.navigation_outcome_unknown = False
         self.state = "ready"
 
     def navigation_failed(self, url: str) -> None:
         self.failed_navigation_url = url
+        self.navigation_outcome_unknown = False
         self.state = "navigation_failed"
 
+    def navigation_unknown(self, url: str) -> None:
+        """A navigation was attempted but whether it happened is unknown."""
+
+        self.page_url = ""
+        self.failed_navigation_url = url
+        self.navigation_outcome_unknown = True
+        self.state = "navigation_unknown"
+
     def discarded(self, state: str) -> None:
         """The browser and its page are gone; nothing earlier is observable."""
 
         self.page_url = ""
         self.failed_navigation_url = ""
+        self.navigation_outcome_unknown = False
         self.state = state
 
     def stale_observation_note(self) -> str:
         if not self.failed_navigation_url:
             return ""
+        if self.navigation_outcome_unknown:
+            return (
+                f"Browser lifecycle: the outcome of the most recent navigation to "
+                f"{self.failed_navigation_url} is unknown. This observation may not "
+                f"show {self.failed_navigation_url}."
+            )
         shown = self.page_url or "an earlier page"
         return (
             f"Browser lifecycle: the most recent navigation to {self.failed_navigation_url} "