fix(display): show reasoning during streaming even when tool calls suppress content

When a model generates content (containing <REASONING_SCRATCHPAD> tags)
alongside tool calls in the same API response, content deltas were
suppressed from streaming once any tool call chunk arrived. This
prevented the CLI's tag extraction from running, so reasoning was
never shown during streaming. The post-response fallback then
displayed reasoning AFTER the already-visible streamed response,
creating a confusing reversed order.

Fix: route suppressed content to stream_delta_callback even when tool
calls are present. The CLI's _stream_delta handles tag extraction —
reasoning tags are routed to the reasoning display box, while
non-reasoning text is handled by the existing stream display logic.
This ensures reasoning appears before tool execution and the final
response, matching the expected visual order.

run_agent.py

@@ -3903,6 +3903,23 @@ class AIAgent:
                         _fire_first_delta()
                         self._fire_stream_delta(delta.content)
                         deltas_were_sent["yes"] = True
+                    else:
+                        # Tool calls suppress regular content streaming (avoids
+                        # displaying chatty "I'll use the tool..." text alongside
+                        # tool calls).  But reasoning tags embedded in suppressed
+                        # content should still reach the display — otherwise the
+                        # reasoning box only appears as a post-response fallback,
+                        # rendering it confusingly after the already-streamed
+                        # response.  Route suppressed content through the stream
+                        # delta callback so its tag extraction can fire the
+                        # reasoning display.  Non-reasoning text is harmlessly
+                        # suppressed by the CLI's _stream_delta when the stream
+                        # box is already closed (tool boundary flush).
+                        if self.stream_delta_callback:
+                            try:
+                                self.stream_delta_callback(delta.content)
+                            except Exception:
+                                pass
 
                 # Accumulate tool call deltas — notify display on first name
                 if delta and delta.tool_calls: