fix(agent): preserve length-recovered output

nanobot/agent/runner.py

@@ -60,6 +60,18 @@ _MAX_LENGTH_RECOVERIES = 3
 _MAX_INJECTIONS_PER_TURN = 3
 _MAX_INJECTION_CYCLES = 5
 
+
+def _restore_outer_whitespace(content: str, original: str | None) -> str:
+    """Restore boundary whitespace stripped while cleaning one recovered segment."""
+    if not original:
+        return content
+    leading_size = len(original) - len(original.lstrip())
+    trailing_size = len(original) - len(original.rstrip())
+    leading = original[:leading_size]
+    trailing = original[-trailing_size:] if trailing_size else ""
+    return f"{leading}{content}{trailing}"
+
+
 @dataclass(slots=True)
 class AgentRunSpec:
     """Configuration for a single agent execution."""
@@ -381,6 +393,9 @@ class AgentRunner:
         workspace_violation_counts: dict[str, int] = {}
         empty_content_retries = 0
         length_recovery_count = 0
+        # Segments from one uninterrupted length-recovery chain. Tool work or
+        # injected user input starts a new logical answer and clears the chain.
+        length_recovery_parts: list[str] = []
         had_injections = False
         injection_cycles = 0
         compacted_tool_call_ids: set[str] = set()
@@ -418,6 +433,7 @@ class AgentRunner:
             context.response = response
             context.tool_calls = list(response.tool_calls)
 
+            original_content = response.content
             reasoning_text, cleaned_content = extract_reasoning(
                 response.reasoning_content,
                 response.thinking_blocks,
@@ -519,6 +535,7 @@ class AgentRunner:
                 )
                 empty_content_retries = 0
                 length_recovery_count = 0
+                length_recovery_parts.clear()
                 # Checkpoint 1: drain injections after tools, before next LLM call
                 _drained, injection_cycles = await self._try_drain_injections(
                     spec, messages, None, injection_cycles,
@@ -567,11 +584,15 @@ class AgentRunner:
                 context.response = response
                 context.usage = dict(raw_usage)
                 context.tool_calls = list(response.tool_calls)
+                original_content = response.content
                 clean = hook.finalize_content(context, response.content)
 
             if response.finish_reason == "length" and not is_blank_text(clean):
                 length_recovery_count += 1
                 if length_recovery_count <= _MAX_LENGTH_RECOVERIES:
+                    length_recovery_parts.append(
+                        _restore_outer_whitespace(clean, original_content)
+                    )
                     logger.info(
                         "Output truncated on turn {} for {} ({}/{}); continuing",
                         iteration,
@@ -614,6 +635,7 @@ class AgentRunner:
                 await hook.on_stream_end(context, resuming=should_continue)
 
             if should_continue:
+                length_recovery_parts.clear()
                 await hook.after_iteration(context)
                 continue
 
@@ -635,6 +657,7 @@ class AgentRunner:
                 )
                 if should_continue:
                     had_injections = True
+                    length_recovery_parts.clear()
                     continue
                 break
             if is_blank_text(clean):
@@ -652,6 +675,7 @@ class AgentRunner:
                 )
                 if should_continue:
                     had_injections = True
+                    length_recovery_parts.clear()
                     continue
                 break
 
@@ -671,7 +695,13 @@ class AgentRunner:
                     "pending_tool_calls": [],
                 },
             )
-            final_content = clean
+            if length_recovery_parts:
+                final_content = (
+                    "".join(length_recovery_parts)
+                    + _restore_outer_whitespace(clean, original_content)
+                ).strip()
+            else:
+                final_content = clean
             context.final_content = final_content
             context.stop_reason = stop_reason
             await hook.after_iteration(context)