fix: render markdown in assistant panels and speed up reasoning-only recovery

Assistant message panels now use Markdown() instead of raw strings, so
bold/italic/lists render properly. Also nudge the model immediately after
tool errors instead of wasting 2 retry iterations in reasoning-only mode.

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

app/agent/loop.py

@@ -153,7 +153,14 @@ class AgentLoop:
                 reasoning_only_streak += 1
                 self._ctx.pop_last_message()
 
-                if reasoning_only_streak >= _MAX_REASONING_RETRIES:
+                # If the last context messages are tool errors, nudge immediately
+                # rather than wasting retries — the model is likely confused by the error.
+                has_recent_tool_error = any(
+                    m.role == "tool" and m.content and m.content.startswith("Unknown ")
+                    for m in self._ctx.get_history()[-3:]
+                )
+
+                if has_recent_tool_error or reasoning_only_streak >= _MAX_REASONING_RETRIES:
                     # Nudge the model by injecting a user hint
                     if self._display:
                         self._display.write_warning(
@@ -162,7 +169,7 @@ class AgentLoop:
                         )
                     self._ctx.add_message(
                         "user",
-                        "Please respond with your answer. Do not just think — provide your actual response.",
+                        "Please respond with your answer. If a tool call failed, briefly explain what happened and continue.",
                     )
                     reasoning_only_streak = 0
                 else:

app/utils/display.py

@@ -10,6 +10,7 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING, Protocol
 
+from rich.markdown import Markdown
 from rich.panel import Panel
 from rich.table import Table
 from rich.text import Text
@@ -50,7 +51,7 @@ def render_user_message(content: str) -> Panel:
 
 def render_assistant_message(content: str) -> Panel:
     """Render an assistant message as a styled panel."""
-    return Panel(content, title="Assistant", border_style="green", expand=True)
+    return Panel(Markdown(content), title="Assistant", border_style="green", expand=True)
 
 
 def render_tool_call(name: str, args: str) -> Text: