fix: clear pending_approval before tool execution starts

Moves session.pending_approval = None to right after parsing approval
decisions, before tool execution begins. Previously it was cleared after
all tools finished, so a page refresh during execution would re-show
the approval dialog.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agent/core/agent_loop.py

@@ -652,6 +652,10 @@ class Handlers:
             else:
                 rejected_tasks.append((tc, tool_name, approval_decision))
 
+        # Clear pending approval immediately so a page refresh during
+        # execution won't re-show the approval dialog.
+        session.pending_approval = None
+
         # Notify frontend of approval decisions immediately (before execution)
         for tc, tool_name, tool_args, _was_edited in approved_tasks:
             await session.send_event(
@@ -780,9 +784,6 @@ class Handlers:
                 )
             )
 
-        # Clear pending approval
-        session.pending_approval = None
-
         # Continue agent loop with empty input to process the tool results
         await Handlers.run_agent(session, "")